PIK3CD

UniProt ID: O00329
Organism: Homo sapiens
Review Status: COMPLETE
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Gene Description

PIK3CD encodes p110delta, the leukocyte-enriched catalytic subunit of class IA phosphoinositide 3-kinase delta. In p85-family regulatory complexes, p110delta phosphorylates membrane phosphoinositides, especially PI(4,5)P2, to generate PIP3 downstream of immune receptors including BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40, Fc receptors, and cytokine/growth-factor receptors. The core curatable function is PIP3-producing lipid kinase activity in PI3K/AKT immune receptor signaling; broad immune phenotypes, chemotaxis, angiogenesis, and migration annotations are supported contextual outputs rather than the core molecular function.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0005737 cytoplasm
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0016477 cell migration
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: Supported cell-migration role in specific leukocyte and glioma contexts, but non-core relative to lipid kinase signaling.
Reason: PIK3CD knockdown decreases glioma-cell migration and PI3Kdelta also affects leukocyte migration; these are downstream context-specific outputs rather than the core function.
Supporting Evidence:
PMID:22079609
Interestingly, knockdown of p110δ decreased the cell migration and invasion ability of all GBM cell lines tested.
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
GO:0005942 phosphatidylinositol 3-kinase complex
IBA
GO_REF:0000033
MODIFY
Summary: The complex assignment is valid but should use the more specific class IA phosphatidylinositol 3-kinase complex term.
Reason: PIK3CD is not just any PI3K-complex component; it is the p110delta catalytic subunit of class IA p85-family regulatory complexes. GO:0005943 captures the correct complex subtype.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
GO:0043491 phosphatidylinositol 3-kinase/protein kinase B signal transduction
IBA
GO_REF:0000033
ACCEPT
Summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated PIP3.
Reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This pathway term captures the central signaling output of PI3Kdelta even when the initiating receptor or cell type differs.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide 3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes downstream of receptor signaling in immune cells, particularly in lymphocytes.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
GO:0036092 phosphatidylinositol-3-phosphate biosynthetic process
IBA
GO_REF:0000033
MODIFY
Summary: The PI3P biosynthetic-process term is too specific for a class III/VPS34-like product and is not the best process term for PIK3CD.
Reason: PIK3CD/p110delta primarily generates PIP3 from PI(4,5)P2 in class IA receptor signaling. A broader phosphatidylinositol phosphate biosynthetic process term better reflects the current GO vocabulary without implying class III PI3P-centered biology.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
Reactome:R-HSA-389158
Upon binding to CD28, the PI3K enzyme catalyzes the phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3).
GO:0048015 phosphatidylinositol-mediated signaling
IBA
GO_REF:0000033
MODIFY
Summary: The phosphatidylinositol-mediated signaling term is correct but too broad for PIK3CD.
Reason: PIK3CD is specifically a class IA PIP3-producing PI3K that feeds PI3K/AKT receptor signaling, so the more specific PI3K/AKT signal-transduction term is preferred.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide 3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes downstream of receptor signaling in immune cells, particularly in lymphocytes.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
GO:0005886 plasma membrane
IBA
GO_REF:0000033
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0016303 1-phosphatidylinositol-3-kinase activity
IBA
GO_REF:0000033
ACCEPT
Summary: Core molecular function as a phosphatidylinositol 3-kinase catalytic subunit.
Reason: This parent PI3K activity term is valid for p110delta, although GO:0046934 is the most specific MF term for its canonical PIP2-to-PIP3 reaction.
Supporting Evidence:
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
GO:0035005 1-phosphatidylinositol-4-phosphate 3-kinase activity
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: Supported phosphoinositide 3-kinase substrate activity, but PI4P phosphorylation is not the primary curatable core activity for PIK3CD.
Reason: Class I PI3Kdelta can act on phosphorylated phosphoinositides, and Reactome includes PIK3CD complexes in PI4P-to-PI(3,4)P2 reactions. The canonical core activity remains PI(4,5)P2-to-PIP3.
Supporting Evidence:
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
Reactome:R-HSA-1676109
These complexes along with phosphatidylinositol-4-phosphate 3-kinase C2 domain-containing subunits alpha (PIK3C2A), beta (PIK3C2B), and gamma (PIK3C2G) phosphorylate phosphatidylinositol 4-phosphate (PI4P) to phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2).
GO:0000166 nucleotide binding
IEA
GO_REF:0000043
MODIFY
Summary: The nucleotide-binding annotation is too generic for a lipid kinase and should be narrowed to ATP binding.
Reason: PIK3CD catalysis uses ATP; the broad nucleotide-binding term loses the catalytic context and is less informative than GO:0005524 ATP binding or the catalytic PI(4,5)P2 3-kinase MF.
Proposed replacements: ATP binding
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
GO:0002250 adaptive immune response
IEA
GO_REF:0000043
KEEP AS NON CORE
Summary: Supported adaptive-immune output, but this is a systems-level consequence of PI3Kdelta immune receptor signaling rather than the core molecular function.
Reason: Human disease genetics and leukocyte studies support a role in adaptive immunity, but the core function should remain PIP3-producing class IA PI3K signaling.
Supporting Evidence:
PMID:27616589
Here, we review the roles of PI3Kδ in adaptive immunity, describe the clinical manifestations and mechanisms of disease in APDS and highlight new insights into PI3Kδ gleaned from these patients, as well as implications of these findings for clinical therapy.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0002376 immune system process
IEA
GO_REF:0000043
MARK AS OVER ANNOTATED
Summary: Correct directionally but too broad to be useful for PIK3CD curation.
Reason: PIK3CD has immune functions, but GO:0002376 is a very broad parent term. More informative annotations are BCR/TCR signaling, PI3K/AKT signaling, and specific leukocyte activation/migration processes.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0002443 leukocyte mediated immunity
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: Supported leukocyte/immune response involvement, but non-core and broad relative to receptor-proximal PI3Kdelta signaling.
Reason: PIK3CD is leukocyte-enriched and affects immune responses, yet this broad immune-process term should not define the core function.
Supporting Evidence:
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
PMID:27616589
Here, we review the roles of PI3Kδ in adaptive immunity, describe the clinical manifestations and mechanisms of disease in APDS and highlight new insights into PI3Kδ gleaned from these patients, as well as implications of these findings for clinical therapy.
GO:0005524 ATP binding
IEA
GO_REF:0000043
KEEP AS NON CORE
Summary: ATP binding is valid for the catalytic kinase domain, but it is generic relative to the core lipid kinase activity.
Reason: ATP is required for PI3Kdelta catalysis, yet ATP binding alone is not a specific description of the gene product function.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
GO:0005737 cytoplasm
IEA
GO_REF:0000044
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005829 cytosol
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005943 phosphatidylinositol 3-kinase complex, class IA
IEA
GO_REF:0000117
ACCEPT
Summary: Correct class IA PI3K complex annotation for p110delta/p85-family regulatory assemblies.
Reason: This is the most specific existing CC term for PIK3CD complex membership and is supported by ComplexPortal entries and synthesis of the class IA p110delta-p85 regulatory complex.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
Reactome:R-HSA-2316434
In unstimulated cells, PI3K class IA exists as an inactive heterodimer of a p85 regulatory subunit (encoded by PIK3R1, PIK3R2 or PIK3R3) and a p110 catalytic subunit (encoded by PIK3CA, PIK3CB or PIK3CD).
GO:0006629 lipid metabolic process
IEA
GO_REF:0000043
MODIFY
Summary: The lipid metabolic process term is directionally correct but too broad for PIK3CD.
Reason: PIK3CD is specifically a phosphoinositide lipid kinase that produces 3-phosphoinositides/PIP3 in signaling contexts; phosphatidylinositol phosphate biosynthesis is the more informative same-aspect process replacement, while the specific PI(4,5)P2 3-kinase molecular function is handled separately.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0006935 chemotaxis
IEA
GO_REF:0000043
MODIFY
Summary: The generic chemotaxis annotation should be narrowed to the specific leukocyte chemotaxis processes supported for PIK3CD.
Reason: The evidence supports T-cell, B-cell, neutrophil, and mast-cell chemotaxis contexts rather than chemotaxis as a broad parent term.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0006954 inflammatory response
IEA
GO_REF:0000043
KEEP AS NON CORE
Summary: Supported inflammatory-response involvement, but it is a downstream physiological output of PI3Kdelta activity.
Reason: PI3Kdelta disruption alters inflammatory responses in vivo and PI3K lipid messengers control leukocyte signaling, but inflammation is a non-core phenotype/process relative to lipid kinase signaling.
Supporting Evidence:
PMID:17290298
Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second messengers that control an array of intracellular signalling pathways that are known to have important roles in leukocytes.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0007166 cell surface receptor signaling pathway
IEA
GO_REF:0000117
MODIFY
Summary: The broad cell-surface receptor signaling annotation should be narrowed to the immune receptor signaling pathways where PIK3CD has strong support.
Reason: PIK3CD acts downstream of immune receptors such as BCR, TCR, and CD28. Those terms are more informative and better supported than the generic cell-surface receptor signaling parent.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for B-cell receptor (BCR) signaling.
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for T-cell receptor (TCR) signaling.
GO:0010595 positive regulation of endothelial cell migration
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: Supported endothelial/angiogenesis context, but non-core and tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
Reason: Cultured endothelial-cell work supports VEGF-induced Akt activation, proliferation, migration, tube formation, and retinal angiogenesis. This is a real contextual role, not the primary leukocyte-enriched core function.
Supporting Evidence:
PMID:31915155
Using genetic and pharmacological approaches, we show that p110δ activity in cultured ECs controls Akt activation, cell proliferation, migration, and tube formation induced by vascular endothelial growth factor, basic fibroblast growth factor, and epidermal growth factor.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
GO:0010628 positive regulation of gene expression
IEA
GO_REF:0000117
MARK AS OVER ANNOTATED
Summary: Over-annotation to positive regulation of gene expression. The available PIK3CD evidence supports upstream PI3K/AKT signaling more directly than this distal transcriptional-output term.
Reason: Gene-expression changes can occur downstream of PI3K/AKT/FOXO signaling, but the evidence supports this as a distal pathway output requiring careful attribution rather than a direct core PIK3CD function. This broad distal term should not be retained as a core annotation.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
It highlights pathway antagonism by PTEN/SHIP and connects FOXO-regulated transcription (e.g., immune differentiation programs) to PI3K signaling outputs (useful for downstream BP annotations, but requires careful evidence attribution if annotating those distal effects).
GO:0016301 kinase activity
IEA
GO_REF:0000120
MODIFY
Summary: The generic enzyme-activity annotation is valid only as a distant parent and should be replaced by the specific lipid kinase activity.
Reason: PIK3CD is not merely a generic kinase/transferase; the evidence supports phosphoinositide 3-kinase activity, especially PI(4,5)P2 3-kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
GO:0016303 1-phosphatidylinositol-3-kinase activity
IEA
GO_REF:0000120
ACCEPT
Summary: Core molecular function as a phosphatidylinositol 3-kinase catalytic subunit.
Reason: This parent PI3K activity term is valid for p110delta, although GO:0046934 is the most specific MF term for its canonical PIP2-to-PIP3 reaction.
Supporting Evidence:
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
GO:0016740 transferase activity
IEA
GO_REF:0000043
MODIFY
Summary: The generic enzyme-activity annotation is valid only as a distant parent and should be replaced by the specific lipid kinase activity.
Reason: PIK3CD is not merely a generic kinase/transferase; the evidence supports phosphoinositide 3-kinase activity, especially PI(4,5)P2 3-kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
GO:0022603 regulation of anatomical structure morphogenesis
IEA
GO_REF:0000117
MARK AS OVER ANNOTATED
Summary: Over-annotation to broad developmental, morphogenesis, or adhesion regulation terms.
Reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but these broad regulation terms over-generalize downstream effects and obscure the better-supported PI3Kdelta receptor-signaling biology.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0030154 cell differentiation
IEA
GO_REF:0000043
MODIFY
Summary: The generic cell differentiation annotation should be narrowed to the specific leukocyte differentiation processes supported for PIK3CD.
Reason: The evidence supports B-cell, T-cell, NK-cell, and mast-cell differentiation contexts rather than undifferentiated cell differentiation as a generic parent.
Supporting Evidence:
PMID:20200404
Thus, we provide novel evidence that p110gamma and p110delta have overlapping and cell-extrinsic roles in the development, peripheral maintenance, and function of B cells.
PMID:17371229
In addition, p110delta regulates the differentiation of peripheral Th (helper T-cells) towards the Th1 and Th2 lineages.
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
GO:0030155 regulation of cell adhesion
IEA
GO_REF:0000117
MARK AS OVER ANNOTATED
Summary: Over-annotation to broad developmental, morphogenesis, or adhesion regulation terms.
Reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but these broad regulation terms over-generalize downstream effects and obscure the better-supported PI3Kdelta receptor-signaling biology.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0033031 positive regulation of neutrophil apoptotic process
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: Supported neutrophil-death/apoptotic-process annotation, but non-core and context-dependent.
Reason: FcαRI-triggered neutrophil death requires class IA PI3K signaling in inflammatory contexts. This supports the annotation as a non-core immune effector process.
Supporting Evidence:
PMID:25339672
preactivation with cytokines or TLR agonists in vitro enhanced FcαRI-mediated death by additional recruitment of caspase-independent pathways, but this required PI3K class IA and MAPK signaling.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0042113 B cell activation
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: Supported B-cell activation/function annotation, but downstream of the more core BCR signaling role.
Reason: PIK3CD is important for B-cell development and function. B-cell activation is real, but BCR signaling and PI3K/AKT signaling are the more precise core process annotations.
Supporting Evidence:
PMID:20200404
Thus, we provide novel evidence that p110gamma and p110delta have overlapping and cell-extrinsic roles in the development, peripheral maintenance, and function of B cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for B-cell receptor (BCR) signaling.
GO:0043491 phosphatidylinositol 3-kinase/protein kinase B signal transduction
IEA
GO_REF:0000120
ACCEPT
Summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated PIP3.
Reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This pathway term captures the central signaling output of PI3Kdelta even when the initiating receptor or cell type differs.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide 3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes downstream of receptor signaling in immune cells, particularly in lymphocytes.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
GO:0045087 innate immune response
IEA
GO_REF:0000120
KEEP AS NON CORE
Summary: Supported innate-immune involvement, but this is a broad non-core immune-system output.
Reason: PI3Kdelta contributes to myeloid and innate leukocyte activities, but the precise core function is receptor-linked PIP3 production rather than innate immunity as a whole.
Supporting Evidence:
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
PMID:17290298
Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second messengers that control an array of intracellular signalling pathways that are known to have important roles in leukocytes.
GO:0046854 phosphatidylinositol phosphate biosynthetic process
IEA
GO_REF:0000002
ACCEPT
Summary: Supported core process output of PI3Kdelta lipid kinase activity.
Reason: PIK3CD produces 3-phosphoinositides, especially PIP3, as the biochemical product of its class IA lipid kinase activity. This process term is broader than an ideal PIP3-biosynthesis term but is correct.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
Reactome:R-HSA-389158
Upon binding to CD28, the PI3K enzyme catalyzes the phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3).
GO:0046934 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity
IEA
GO_REF:0000120
ACCEPT
Summary: Core specific molecular function: p110delta phosphorylates PI(4,5)P2 to generate PIP3.
Reason: PI(4,5)P2 3-kinase activity is the specific catalytic activity that drives PI3Kdelta receptor signaling and PIP3-dependent AKT pathway recruitment.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
Reactome:R-HSA-389158
Upon binding to CD28, the PI3K enzyme catalyzes the phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3).
GO:0051094 positive regulation of developmental process
IEA
GO_REF:0000117
MARK AS OVER ANNOTATED
Summary: Over-annotation to broad developmental, morphogenesis, or adhesion regulation terms.
Reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but these broad regulation terms over-generalize downstream effects and obscure the better-supported PI3Kdelta receptor-signaling biology.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0051240 positive regulation of multicellular organismal process
IEA
GO_REF:0000117
MARK AS OVER ANNOTATED
Summary: Over-annotation to broad developmental, morphogenesis, or adhesion regulation terms.
Reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but these broad regulation terms over-generalize downstream effects and obscure the better-supported PI3Kdelta receptor-signaling biology.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:2000026 regulation of multicellular organismal development
IEA
GO_REF:0000117
MARK AS OVER ANNOTATED
Summary: Over-annotation to broad developmental, morphogenesis, or adhesion regulation terms.
Reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but these broad regulation terms over-generalize downstream effects and obscure the better-supported PI3Kdelta receptor-signaling biology.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0005515 protein binding
IPI
PMID:21827948
Dynamics of the phosphoinositide 3-kinase p110δ interaction ...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005515 protein binding
IPI
PMID:22020336
p37δ is a new isoform of PI3K p110δ that increases cell prol...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005515 protein binding
IPI
PMID:24165795
Dominant-activating germline mutations in the gene encoding ...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005515 protein binding
IPI
PMID:28514442
Architecture of the human interactome defines protein commun...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005515 protein binding
IPI
PMID:31031754
Case Study: Mechanism for Increased Follicular Helper T Cell...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005515 protein binding
IPI
PMID:32296183
A reference map of the human binary protein interactome.
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005515 protein binding
IPI
PMID:33961781
Dual proteome-scale networks reveal cell-specific remodeling...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005515 protein binding
IPI
PMID:35271311
OpenCell: Endogenous tagging for the cartography of human ce...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005515 protein binding
IPI
PMID:40205054
Multimodal cell maps as a foundation for structural and func...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0005829 cytosol
IDA
GO_REF:0000052
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005515 protein binding
IPI
PMID:32606397
PI3K activation is enhanced by FOXM1D binding to p110 and p8...
MARK AS OVER ANNOTATED
Summary: Protein binding is an uninformative over-annotation for PIK3CD.
Reason: PIK3CD does interact with p85-family regulatory subunits and other signaling proteins, but GO:0005515 does not capture the meaningful function. The informative annotations are class IA PI3K complex membership and phosphoinositide kinase activity.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
GO:0031295 T cell costimulation
TAS
Reactome:R-HSA-389356
ACCEPT
Summary: Supported CD28/T-cell costimulation context for PI3Kdelta signaling.
Reason: CD28 is a direct immune receptor context in which PI3K participates in costimulatory signaling and PIP3 generation. This is part of the core immune-receptor signaling frame for PIK3CD.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
Reactome:R-HSA-389356
The cytoplasmic tail of CD28, upon ligand binding, undergoes phosphorylation by Src family kinases like LCK and FYN, triggering downstream signaling pathways involving PI3K, VAV-1, Tec family kinases, AKT, and other adaptor proteins (Sharpe & Freeman 2002; Chen & Flies 2013).
Reactome:R-HSA-389158
Upon binding to CD28, the PI3K enzyme catalyzes the phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3).
GO:0046934 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity
TAS
Reactome:R-HSA-389158
ACCEPT
Summary: Core specific molecular function: p110delta phosphorylates PI(4,5)P2 to generate PIP3.
Reason: PI(4,5)P2 3-kinase activity is the specific catalytic activity that drives PI3Kdelta receptor signaling and PIP3-dependent AKT pathway recruitment.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
Reactome:R-HSA-389158
Upon binding to CD28, the PI3K enzyme catalyzes the phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3).
GO:0006955 immune response
NAS
PMID:27616589
PI3Kδ and primary immunodeficiencies.
KEEP AS NON CORE
Summary: Supported leukocyte/immune response involvement, but non-core and broad relative to receptor-proximal PI3Kdelta signaling.
Reason: PIK3CD is leukocyte-enriched and affects immune responses, yet this broad immune-process term should not define the core function.
Supporting Evidence:
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
PMID:27616589
Here, we review the roles of PI3Kδ in adaptive immunity, describe the clinical manifestations and mechanisms of disease in APDS and highlight new insights into PI3Kδ gleaned from these patients, as well as implications of these findings for clinical therapy.
GO:0030183 B cell differentiation
NAS
PMID:20200404
The catalytic PI3K isoforms p110gamma and p110delta contribu...
KEEP AS NON CORE
Summary: Supported B-cell differentiation/development role, but non-core relative to PI3Kdelta catalytic signaling.
Reason: B-cell developmental phenotypes are well supported, but they are downstream organism/cell lineage consequences of PIP3-producing PI3Kdelta signaling.
Supporting Evidence:
PMID:20200404
Thus, we provide novel evidence that p110gamma and p110delta have overlapping and cell-extrinsic roles in the development, peripheral maintenance, and function of B cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for B-cell receptor (BCR) signaling.
GO:0030217 T cell differentiation
NAS
PMID:17371229
The PI3K p110delta controls T-cell development, differentiat...
KEEP AS NON CORE
Summary: Supported T-cell differentiation role, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: T-cell differentiation is a supported immune-cell outcome of p110delta activity, not the core molecular function itself.
Supporting Evidence:
PMID:17371229
In addition, p110delta regulates the differentiation of peripheral Th (helper T-cells) towards the Th1 and Th2 lineages.
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
GO:0038084 vascular endothelial growth factor signaling pathway
IGI
PMID:31915155
PI3Kδ as a Novel Therapeutic Target in Pathological Angiogen...
KEEP AS NON CORE
Summary: Supported endothelial/angiogenesis context, but non-core and tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
Reason: Cultured endothelial-cell work supports VEGF-induced Akt activation, proliferation, migration, tube formation, and retinal angiogenesis. This is a real contextual role, not the primary leukocyte-enriched core function.
Supporting Evidence:
PMID:31915155
Using genetic and pharmacological approaches, we show that p110δ activity in cultured ECs controls Akt activation, cell proliferation, migration, and tube formation induced by vascular endothelial growth factor, basic fibroblast growth factor, and epidermal growth factor.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
GO:0010595 positive regulation of endothelial cell migration
IGI
PMID:31915155
PI3Kδ as a Novel Therapeutic Target in Pathological Angiogen...
KEEP AS NON CORE
Summary: Supported endothelial/angiogenesis context, but non-core and tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
Reason: Cultured endothelial-cell work supports VEGF-induced Akt activation, proliferation, migration, tube formation, and retinal angiogenesis. This is a real contextual role, not the primary leukocyte-enriched core function.
Supporting Evidence:
PMID:31915155
Using genetic and pharmacological approaches, we show that p110δ activity in cultured ECs controls Akt activation, cell proliferation, migration, and tube formation induced by vascular endothelial growth factor, basic fibroblast growth factor, and epidermal growth factor.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
GO:0001938 positive regulation of endothelial cell proliferation
IGI
PMID:31915155
PI3Kδ as a Novel Therapeutic Target in Pathological Angiogen...
KEEP AS NON CORE
Summary: Supported endothelial/angiogenesis context, but non-core and tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
Reason: Cultured endothelial-cell work supports VEGF-induced Akt activation, proliferation, migration, tube formation, and retinal angiogenesis. This is a real contextual role, not the primary leukocyte-enriched core function.
Supporting Evidence:
PMID:31915155
Using genetic and pharmacological approaches, we show that p110δ activity in cultured ECs controls Akt activation, cell proliferation, migration, and tube formation induced by vascular endothelial growth factor, basic fibroblast growth factor, and epidermal growth factor.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
GO:0043491 phosphatidylinositol 3-kinase/protein kinase B signal transduction
IGI
PMID:31915155
PI3Kδ as a Novel Therapeutic Target in Pathological Angiogen...
ACCEPT
Summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated PIP3.
Reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This pathway term captures the central signaling output of PI3Kdelta even when the initiating receptor or cell type differs.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide 3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes downstream of receptor signaling in immune cells, particularly in lymphocytes.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
GO:0045766 positive regulation of angiogenesis
ISS
GO_REF:0000024
KEEP AS NON CORE
Summary: Supported endothelial/angiogenesis context, but non-core and tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
Reason: Cultured endothelial-cell work supports VEGF-induced Akt activation, proliferation, migration, tube formation, and retinal angiogenesis. This is a real contextual role, not the primary leukocyte-enriched core function.
Supporting Evidence:
PMID:31915155
Using genetic and pharmacological approaches, we show that p110δ activity in cultured ECs controls Akt activation, cell proliferation, migration, and tube formation induced by vascular endothelial growth factor, basic fibroblast growth factor, and epidermal growth factor.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
GO:1905278 positive regulation of epithelial tube formation
IGI
PMID:31915155
PI3Kδ as a Novel Therapeutic Target in Pathological Angiogen...
KEEP AS NON CORE
Summary: Supported endothelial/angiogenesis context, but non-core and tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
Reason: Cultured endothelial-cell work supports VEGF-induced Akt activation, proliferation, migration, tube formation, and retinal angiogenesis. This is a real contextual role, not the primary leukocyte-enriched core function.
Supporting Evidence:
PMID:31915155
Using genetic and pharmacological approaches, we show that p110δ activity in cultured ECs controls Akt activation, cell proliferation, migration, and tube formation induced by vascular endothelial growth factor, basic fibroblast growth factor, and epidermal growth factor.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
GO:0033031 positive regulation of neutrophil apoptotic process
IMP
PMID:25339672
Human IgA Fc receptor FcαRI (CD89) triggers different forms ...
KEEP AS NON CORE
Summary: Supported neutrophil-death/apoptotic-process annotation, but non-core and context-dependent.
Reason: FcαRI-triggered neutrophil death requires class IA PI3K signaling in inflammatory contexts. This supports the annotation as a non-core immune effector process.
Supporting Evidence:
PMID:25339672
preactivation with cytokines or TLR agonists in vitro enhanced FcαRI-mediated death by additional recruitment of caspase-independent pathways, but this required PI3K class IA and MAPK signaling.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0043491 phosphatidylinositol 3-kinase/protein kinase B signal transduction
IMP
PMID:25339672
Human IgA Fc receptor FcαRI (CD89) triggers different forms ...
ACCEPT
Summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated PIP3.
Reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This pathway term captures the central signaling output of PI3Kdelta even when the initiating receptor or cell type differs.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide 3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes downstream of receptor signaling in immune cells, particularly in lymphocytes.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
GO:0001779 natural killer cell differentiation
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported NK-cell differentiation role, but non-core relative to PI3Kdelta catalytic signaling.
Reason: PI3Kdelta participates in NK-cell development and migration, but this is a leukocyte-specific cellular outcome rather than the core lipid kinase function.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
GO:0001819 positive regulation of cytokine production
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported cytokine-production role, but non-core and downstream of immune receptor signaling.
Reason: Cytokine-production changes are leukocyte outputs of PI3Kdelta signaling, not the primary biochemical function.
Supporting Evidence:
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for T-cell receptor (TCR) signaling.
GO:0002250 adaptive immune response
TAS
PMID:17290298
PI3K delta and PI3K gamma: partners in crime in inflammation...
KEEP AS NON CORE
Summary: Supported adaptive-immune output, but this is a systems-level consequence of PI3Kdelta immune receptor signaling rather than the core molecular function.
Reason: Human disease genetics and leukocyte studies support a role in adaptive immunity, but the core function should remain PIP3-producing class IA PI3K signaling.
Supporting Evidence:
PMID:27616589
Here, we review the roles of PI3Kδ in adaptive immunity, describe the clinical manifestations and mechanisms of disease in APDS and highlight new insights into PI3Kδ gleaned from these patients, as well as implications of these findings for clinical therapy.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0002551 mast cell chemotaxis
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: PI3Kdelta affects migration of multiple leukocyte types, but these are cell-type-specific outputs of the core PIP3-generating immune signaling function.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0002679 respiratory burst involved in defense response
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported neutrophil respiratory-burst role, but non-core relative to the catalytic PI3Kdelta signaling function.
Reason: PI3Kdelta contributes to neutrophil respiratory burst as a myeloid effector output, but this is not the core molecular function.
Supporting Evidence:
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0006954 inflammatory response
TAS
PMID:17290298
PI3K delta and PI3K gamma: partners in crime in inflammation...
KEEP AS NON CORE
Summary: Supported inflammatory-response involvement, but it is a downstream physiological output of PI3Kdelta activity.
Reason: PI3Kdelta disruption alters inflammatory responses in vivo and PI3K lipid messengers control leukocyte signaling, but inflammation is a non-core phenotype/process relative to lipid kinase signaling.
Supporting Evidence:
PMID:17290298
Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second messengers that control an array of intracellular signalling pathways that are known to have important roles in leukocytes.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0006954 inflammatory response
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported inflammatory-response involvement, but it is a downstream physiological output of PI3Kdelta activity.
Reason: PI3Kdelta disruption alters inflammatory responses in vivo and PI3K lipid messengers control leukocyte signaling, but inflammation is a non-core phenotype/process relative to lipid kinase signaling.
Supporting Evidence:
PMID:17290298
Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second messengers that control an array of intracellular signalling pathways that are known to have important roles in leukocytes.
PMID:20940048
As a result of the broad effects of PI3Kδ in leukocyte functions, the disruption of PI3Kδ expression or activity leads to decreased inflammatory and immune responses in vivo.
GO:0010818 T cell chemotaxis
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: PI3Kdelta affects migration of multiple leukocyte types, but these are cell-type-specific outputs of the core PIP3-generating immune signaling function.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0016303 1-phosphatidylinositol-3-kinase activity
TAS
PMID:17290298
PI3K delta and PI3K gamma: partners in crime in inflammation...
ACCEPT
Summary: Core molecular function as a phosphatidylinositol 3-kinase catalytic subunit.
Reason: This parent PI3K activity term is valid for p110delta, although GO:0046934 is the most specific MF term for its canonical PIP2-to-PIP3 reaction.
Supporting Evidence:
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
GO:0030101 natural killer cell activation
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported NK-cell activation context, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: NK-cell activation is a supported immune output; the central curatable function remains PI3Kdelta PIP3 production in leukocyte signaling.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
GO:0030217 T cell differentiation
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported T-cell differentiation role, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: T-cell differentiation is a supported immune-cell outcome of p110delta activity, not the core molecular function itself.
Supporting Evidence:
PMID:17371229
In addition, p110delta regulates the differentiation of peripheral Th (helper T-cells) towards the Th1 and Th2 lineages.
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
GO:0030593 neutrophil chemotaxis
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: PI3Kdelta affects migration of multiple leukocyte types, but these are cell-type-specific outputs of the core PIP3-generating immune signaling function.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0035747 natural killer cell chemotaxis
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: PI3Kdelta affects migration of multiple leukocyte types, but these are cell-type-specific outputs of the core PIP3-generating immune signaling function.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0035754 B cell chemotaxis
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: PI3Kdelta affects migration of multiple leukocyte types, but these are cell-type-specific outputs of the core PIP3-generating immune signaling function.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0042110 T cell activation
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported T-cell activation/function annotation, but downstream of the more core TCR/CD28 signaling role.
Reason: PIK3CD contributes to T-cell development, activation, and migration. The T-cell activation process is supported but is a cellular outcome of the core TCR/CD28 PI3K signaling function.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for T-cell receptor (TCR) signaling.
GO:0042113 B cell activation
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported B-cell activation/function annotation, but downstream of the more core BCR signaling role.
Reason: PIK3CD is important for B-cell development and function. B-cell activation is real, but BCR signaling and PI3K/AKT signaling are the more precise core process annotations.
Supporting Evidence:
PMID:20200404
Thus, we provide novel evidence that p110gamma and p110delta have overlapping and cell-extrinsic roles in the development, peripheral maintenance, and function of B cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for B-cell receptor (BCR) signaling.
GO:0043303 mast cell degranulation
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported mast-cell degranulation role, but non-core relative to the catalytic PI3Kdelta function.
Reason: PI3Kdelta contributes to mast-cell degranulation, but this is a cell-type-specific effector output rather than the core molecular function.
Supporting Evidence:
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0043491 phosphatidylinositol 3-kinase/protein kinase B signal transduction
TAS
PMID:17290298
PI3K delta and PI3K gamma: partners in crime in inflammation...
ACCEPT
Summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated PIP3.
Reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This pathway term captures the central signaling output of PI3Kdelta even when the initiating receptor or cell type differs.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide 3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes downstream of receptor signaling in immune cells, particularly in lymphocytes.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
PMID:20940048
PI3Kδ is a lipid kinase of the PI3K class IA family involved in early signaling events of leukocytes responding to a wide variety of stimuli.
GO:0045087 innate immune response
TAS
PMID:17290298
PI3K delta and PI3K gamma: partners in crime in inflammation...
KEEP AS NON CORE
Summary: Supported innate-immune involvement, but this is a broad non-core immune-system output.
Reason: PI3Kdelta contributes to myeloid and innate leukocyte activities, but the precise core function is receptor-linked PIP3 production rather than innate immunity as a whole.
Supporting Evidence:
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
PMID:17290298
Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second messengers that control an array of intracellular signalling pathways that are known to have important roles in leukocytes.
GO:0045087 innate immune response
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported innate-immune involvement, but this is a broad non-core immune-system output.
Reason: PI3Kdelta contributes to myeloid and innate leukocyte activities, but the precise core function is receptor-linked PIP3 production rather than innate immunity as a whole.
Supporting Evidence:
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
PMID:17290298
Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second messengers that control an array of intracellular signalling pathways that are known to have important roles in leukocytes.
GO:0050852 T cell receptor signaling pathway
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
ACCEPT
Summary: Supported TCR signaling role for PI3Kdelta.
Reason: UniProt and the literature synthesis identify p110delta as required for TCR signaling, making this one of the core immune receptor signaling processes for PIK3CD.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for T-cell receptor (TCR) signaling.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
GO:0050853 B cell receptor signaling pathway
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
ACCEPT
Summary: Supported BCR signaling role for PI3Kdelta.
Reason: p110delta is required for BCR signaling and B-cell functional outputs; this is one of the strongest process annotations for PIK3CD.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
Required for B-cell receptor (BCR) signaling.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
PMID:20200404
Thus, we provide novel evidence that p110gamma and p110delta have overlapping and cell-extrinsic roles in the development, peripheral maintenance, and function of B cells.
GO:0060374 mast cell differentiation
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported mast-cell differentiation role, but non-core relative to the catalytic PI3Kdelta function.
Reason: Mast-cell maturation/differentiation is a supported leukocyte-cell output of PI3Kdelta signaling, not the core molecular activity.
Supporting Evidence:
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0072672 neutrophil extravasation
TAS
PMID:20940048
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signali...
KEEP AS NON CORE
Summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core relative to receptor-proximal PI3Kdelta signaling.
Reason: PI3Kdelta affects migration of multiple leukocyte types, but these are cell-type-specific outputs of the core PIP3-generating immune signaling function.
Supporting Evidence:
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
PMID:20940048
The role of PI3Kδ in myeloid cell activities, such as inflammation driven cell infiltration, neutrophil oxidative burst, immune complex mediated macrophage activation, as well as mast cell maturation and degranulation, has been well illustrated in various studies.
GO:0010628 positive regulation of gene expression
IMP
PMID:22079609
The catalytic phosphoinositol 3-kinase isoform p110δ is requ...
MARK AS OVER ANNOTATED
Summary: Over-annotation to positive regulation of gene expression. The available PIK3CD evidence supports upstream PI3K/AKT signaling more directly than this distal transcriptional-output term.
Reason: Gene-expression changes can occur downstream of PI3K/AKT/FOXO signaling, but the evidence supports this as a distal pathway output requiring careful attribution rather than a direct core PIK3CD function. This broad distal term should not be retained as a core annotation.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
It highlights pathway antagonism by PTEN/SHIP and connects FOXO-regulated transcription (e.g., immune differentiation programs) to PI3K signaling outputs (useful for downstream BP annotations, but requires careful evidence attribution if annotating those distal effects).
GO:0030335 positive regulation of cell migration
IMP
PMID:22079609
The catalytic phosphoinositol 3-kinase isoform p110δ is requ...
KEEP AS NON CORE
Summary: Supported cell-migration role in specific leukocyte and glioma contexts, but non-core relative to lipid kinase signaling.
Reason: PIK3CD knockdown decreases glioma-cell migration and PI3Kdelta also affects leukocyte migration; these are downstream context-specific outputs rather than the core function.
Supporting Evidence:
PMID:22079609
Interestingly, knockdown of p110δ decreased the cell migration and invasion ability of all GBM cell lines tested.
PMID:20940048
PI3Kδ participates in the development, activation and migration of T cells and NK cells.
GO:0005829 cytosol
TAS
Reactome:R-HSA-1676048
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005829 cytosol
TAS
Reactome:R-HSA-1676109
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005829 cytosol
TAS
Reactome:R-HSA-9012657
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005829 cytosol
TAS
Reactome:R-HSA-9021627
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005829 cytosol
TAS
Reactome:R-HSA-9027275
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005829 cytosol
TAS
Reactome:R-HSA-9606887
KEEP AS NON CORE
Summary: Supported cytoplasmic or cytosolic localization, but this is the resting/general pool rather than the most informative activated signaling site.
Reason: UniProt records cytoplasmic localization and the deep research report describes resting p110delta-p85 complexes as cytosolic. The functionally decisive event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be treated as the core location.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-uniprot.txt
SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-2045911
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-2076220
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-2316434
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-2400009
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-388830
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-388832
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-389158
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-508247
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-879917
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-8854905
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-912627
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-914182
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005886 plasma membrane
TAS
Reactome:R-HSA-9606887
ACCEPT
Summary: Supported core activated-site localization. PI3Kdelta is recruited to plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates reside.
Reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2 substrate is membrane localized and receptor phosphotyrosine signals recruit the p85-p110delta complex to the plasma membrane.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside.
Reactome:R-HSA-1676048
At the plasma membrane, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunits form complexes with regulatory subunits.
GO:0005942 phosphatidylinositol 3-kinase complex
NAS
PMID:9113989
P110delta, a novel phosphoinositide 3-kinase in leukocytes.
MODIFY
Summary: The complex assignment is valid but should use the more specific class IA phosphatidylinositol 3-kinase complex term.
Reason: PIK3CD is not just any PI3K-complex component; it is the p110delta catalytic subunit of class IA p85-family regulatory complexes. GO:0005943 captures the correct complex subtype.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
GO:0005942 phosphatidylinositol 3-kinase complex
NAS
PMID:9235916
p110delta, a novel phosphatidylinositol 3-kinase catalytic s...
MODIFY
Summary: The complex assignment is valid but should use the more specific class IA phosphatidylinositol 3-kinase complex term.
Reason: PIK3CD is not just any PI3K-complex component; it is the p110delta catalytic subunit of class IA p85-family regulatory complexes. GO:0005943 captures the correct complex subtype.
Supporting Evidence:
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells.
file:human/PIK3CD/PIK3CD-uniprot.txt
ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
GO:0006468 protein phosphorylation
NAS
PMID:9113989
P110delta, a novel phosphoinositide 3-kinase in leukocytes.
MODIFY
Summary: Over-annotation to protein phosphorylation. PIK3CD is primarily a phosphoinositide lipid kinase, not a protein kinase.
Reason: PMID:9113989 reports lipid substrate specificity and explicitly distinguishes p110delta from p110alpha by noting that it does not phosphorylate p85, despite intrinsic autophosphorylation. The same-aspect replacement should be lipid phosphorylation rather than general protein phosphorylation; the specific PI(4,5)P2 3-kinase molecular function is handled separately.
Proposed replacements: lipid phosphorylation
Supporting Evidence:
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
PMID:9113989
Unlike p110alpha, p110delta does not phosphorylate p85 but instead harbors an intrinsic autophosphorylation capacity.
GO:0007165 signal transduction
NAS
PMID:9113989
P110delta, a novel phosphoinositide 3-kinase in leukocytes.
MODIFY
Summary: The generic signal-transduction annotation should be narrowed to PI3K/AKT and immune receptor signaling.
Reason: PIK3CD participates in signaling by generating PIP3 downstream of receptor activation. The generic signal transduction parent obscures the specific PI3K/AKT, BCR, and TCR pathways supported by the evidence.
Supporting Evidence:
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
GO:0016303 1-phosphatidylinositol-3-kinase activity
NAS
PMID:9235916
p110delta, a novel phosphatidylinositol 3-kinase catalytic s...
ACCEPT
Summary: Core molecular function as a phosphatidylinositol 3-kinase catalytic subunit.
Reason: This parent PI3K activity term is valid for p110delta, although GO:0046934 is the most specific MF term for its canonical PIP2-to-PIP3 reaction.
Supporting Evidence:
PMID:9235916
Recombinant p110delta phosphorylates phosphatidylinositol and coimmunoprecipitates with p85.
PMID:9113989
p110delta displays a broad phosphoinositide lipid substrate specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins and with GTP-bound Ras.
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.

Core Functions

PIK3CD/p110delta is the leukocyte-enriched class IA PI3K catalytic subunit that forms p85-family regulatory complexes and generates PIP3 from PI(4,5)P2 at receptor-activated membranes.

Supporting Evidence:
  • file:human/PIK3CD/PIK3CD-deep-research-falcon.md
    **PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide 3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes downstream of receptor signaling in immune cells, particularly in lymphocytes.
  • file:human/PIK3CD/PIK3CD-deep-research-falcon.md
    Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
  • file:human/PIK3CD/PIK3CD-deep-research-falcon.md
    In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD.
  • Reactome:R-HSA-389158
    Upon binding to CD28, the PI3K enzyme catalyzes the phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3).
  • file:human/PIK3CD/PIK3CD-uniprot.txt
    ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex class IA, p110delta/p85alpha.

References

Gene Ontology annotation through association of InterPro records with GO terms
Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Gene Ontology annotation based on curation of immunofluorescence data
Electronic Gene Ontology annotations created by ARBA machine learning models
Combined Automated Annotation using Multiple IEA Methods
PI3K delta and PI3K gamma: partners in crime in inflammation in rheumatoid arthritis and beyond?
The PI3K p110delta controls T-cell development, differentiation and regulation.
The catalytic PI3K isoforms p110gamma and p110delta contribute to B cell development and maintenance, transformation, and proliferation.
Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signaling and function.
Dynamics of the phosphoinositide 3-kinase p110δ interaction with p85α and membranes reveals aspects of regulation distinct from p110α.
p37δ is a new isoform of PI3K p110δ that increases cell proliferation and is overexpressed in tumors.
The catalytic phosphoinositol 3-kinase isoform p110δ is required for glioma cell migration and invasion.
Dominant-activating germline mutations in the gene encoding the PI(3)K catalytic subunit p110δ result in T cell senescence and human immunodeficiency.
Human IgA Fc receptor FcαRI (CD89) triggers different forms of neutrophil death depending on the inflammatory microenvironment.
PI3Kδ and primary immunodeficiencies.
Architecture of the human interactome defines protein communities and disease networks.
Case Study: Mechanism for Increased Follicular Helper T Cell Development in Activated PI3K Delta Syndrome.
PI3Kδ as a Novel Therapeutic Target in Pathological Angiogenesis.
A reference map of the human binary protein interactome.
PI3K activation is enhanced by FOXM1D binding to p110 and p85 subunits.
Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.
OpenCell: Endogenous tagging for the cartography of human cellular organization.
Multimodal cell maps as a foundation for structural and functional genomics.
P110delta, a novel phosphoinositide 3-kinase in leukocytes.
p110delta, a novel phosphatidylinositol 3-kinase catalytic subunit that associates with p85 and is expressed predominantly in leukocytes.
Reactome:R-HSA-1676048
PI(4,5)P2 is phosphorylated to PI(3,4,5)P3 by PIK3C[1] at the plasma membrane
Reactome:R-HSA-1676109
PI4P is phosphorylated to PI(3,4)P2 by PI3K3C[2] at the plasma membrane
Reactome:R-HSA-2045911
BCAP Signalosome phosphorylates PI(4,5)P2 forming PI(3,4,5)P3
Reactome:R-HSA-2076220
CD19 Signalosome phosphorylates PI(4,5)P2 forming PI(3,4,5)P3
Reactome:R-HSA-2316434
PI3K phosphorylates PIP2 to PIP3
Reactome:R-HSA-2400009
PI3K inhibitors block PI3K catalytic activity
Reactome:R-HSA-388830
PI3K binds ICOS
Reactome:R-HSA-388832
PI3K binds CD28
Reactome:R-HSA-389158
CD28 bound PI3K phosphorylates PIP2 to PIP3
Reactome:R-HSA-389356
Co-stimulation by CD28
Reactome:R-HSA-508247
Gab2 binds the p85 subunit of Class 1A PI3 kinases
Reactome:R-HSA-879917
CBL, GRB2, FYN and PI3K p85 subunit are constitutively associated
Reactome:R-HSA-8854905
p-5Y-GAB in the RET-GRB2-GAB complexes binds p85-PI3K
Reactome:R-HSA-9012657
EPO:phospho-EPOR:phospho-JAK2:LYN:phospho-IRS2 binds PI3K
Reactome:R-HSA-9021627
EPOR-associated PI3K phosphorylates PIP2 to PIP3
Reactome:R-HSA-9027275
EPO:phospho-EPOR:phospho-JAK2:LYN:IRS2:phospho-GAB1 binds PI3K
Reactome:R-HSA-912627
CBL ubiquitinates PI3K
Reactome:R-HSA-914182
14-3-3 zeta binding allows recruitment of PI3K
Reactome:R-HSA-9606887
p-CD19:VAV binds PI3K and GRB2
file:human/PIK3CD/PIK3CD-deep-research-falcon.md
Falcon deep research report on PIK3CD
file:human/PIK3CD/PIK3CD-uniprot.txt
UniProtKB record for PIK3CD

Suggested Questions for Experts

Q: Which PIK3CD-dependent leukocyte migration, neutrophil death, and endothelial angiogenesis annotations remain physiologically relevant in human primary cells after controlling for class I PI3K isoform redundancy and inhibitor selectivity?

Q: Should GO include a more specific biological-process term for class I PI3K-mediated PI(3,4,5)P3 biosynthesis to avoid using PI3P-centered or overly broad phosphatidylinositol phosphate biosynthetic process terms for PIK3CD?

Suggested Experiments

Experiment: Use isoform-selective genetic rescue in human primary B and T cells to separate PIK3CD-specific BCR, TCR, and CD28 signaling outputs from overlapping PIK3CA/PIK3CB/PIK3CG class I PI3K activity.

Type: primary-cell genetic rescue and phosphoprotein/PIP3 readout

Experiment: Measure PI(4,5)P2-to-PIP3 and PI4P-to-PI(3,4)P2 product formation for p110delta-p85 complexes under matched in vitro and membrane-recruitment conditions to clarify whether PI4P kinase annotations should remain non-core.

Type: lipid kinase substrate-specificity assay

Deep Research

Falcon

(PIK3CD-deep-research-falcon.md)
GO-focused deep research report: human **PIK3CD** (UniProt O00329; PI3K p110δ) Falcon Edison Scientific Literature 26 citations 2026-05-12T10:05:46.915578

GO-focused deep research report: human PIK3CD (UniProt O00329; PI3K p110δ)

0) Gene/product synopsis (annotation scope)

PIK3CD encodes the catalytic subunit p110δ of class IA phosphoinositide 3-kinase (PI3Kδ), a lipid kinase that produces PI(3,4,5)P3 (PIP3) at membranes downstream of receptor signaling in immune cells, particularly in lymphocytes. p110δ acts as a heterodimer with p85-family regulatory subunits, and receptor-triggered recruitment/relief of p85 inhibition is central to its regulated activity. (ijspeert2024hyperactivationofthe pages 2-4, ijspeert2024hyperactivationofthe pages 1-2)

Canonical record for protein identity: UniProt O00329 (https://www.uniprot.org/uniprotkb/O00329/). (No UniProt text was retrieved via tools; URL provided for curator convenience.)

1) Key GO concepts and definitions (current understanding)

1.1 Molecular function (MF): what p110δ does biochemically

Core enzymatic activity (lipid phosphorylation at D3 position): Class I PI3Ks phosphorylate membrane inositol phospholipids at the 3′ position; class IA enzymes (including p110δ) act on PI(4,5)P2 to generate PIP3, which serves as a membrane docking lipid for downstream signaling proteins. (ijspeert2024hyperactivationofthe pages 1-2, stokoe2005thephosphoinositide3kinase pages 1-3)

ATP dependence / catalytic-site context: PI3Kδ catalysis requires ATP; this is strongly supported indirectly by inhibitor mechanism studies contrasting ATP-competitive inhibitors (idelalisib) with non–ATP-competitive allosteric PI3Kδ inhibition (IOA-244), which alters enzyme kinetics consistent with catalytic-site ATP usage in the reaction. (johnson2023ioa244isa pages 6-7)

1.2 Cellular component (CC): where p110δ is and what complex it is part of

Class IA PI3K complex membership: Class IA PI3Ks function as heterodimers of p110 catalytic subunits and p85-family regulatory subunits; p85 stabilizes and inhibits p110 in resting state. (ijspeert2024hyperactivationofthe pages 2-4, stokoe2005thephosphoinositide3kinase pages 1-3)

Membrane recruitment as a key localization event: Upon receptor activation, p85 SH2 domains bind phosphotyrosine motifs (e.g., YxxM-containing motifs) on receptors/adaptors, recruiting the p85–p110δ complex to the plasma membrane, where phosphoinositide substrates reside and catalytic activity increases. (ijspeert2024hyperactivationofthe pages 2-4, stokoe2005thephosphoinositide3kinase pages 1-3)

1.3 Biological process (BP): what p110δ does in cells/tissues

PI3K→AKT→mTOR/FOXO axis: PIP3 recruits AKT to the plasma membrane for phosphorylation (PDK1/mTORC2 context) and downstream regulation of mTORC1/S6 and FOXO transcription factor localization/function. (ijspeert2024hyperactivationofthe pages 2-4, ijspeert2024hyperactivationofthe pages 1-2)

Immune receptor signaling context: In immune cells, class IA PI3K (including p110δ) propagates signaling downstream of BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40 (and related receptor/adaptor systems), framing the major immune-cell BP terms relevant for PIK3CD. (ijspeert2024hyperactivationofthe pages 2-4)

2) Major immune-cell signaling roles with key experimental evidence (curation-relevant)

2.1 B cell receptor (BCR) signaling and Ca2+ mobilization (high-confidence genetic evidence)

A foundational genetic study using p110δ-deficient mice demonstrates that p110δ is essential and nonredundant for effective BCR signaling.

Key experimental findings (Mol Cell Biol, 2002-12; DOI:10.1128/MCB.22.24.8580-8591.2002; URL: https://doi.org/10.1128/mcb.22.24.8580-8591.2002):
- Anti-IgM–induced intracellular Ca2+ mobilization in p110δ−/− B cells was reduced to ~25% of wild type, while ionomycin response was preserved, indicating a BCR-proximal signaling defect requiring p110δ. (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole media 9f8002cf)
- Proximal BCR signaling events (e.g., Btk and PLCγ2 tyrosine phosphorylation) occurred comparably, consistent with p110δ acting in the pathway needed for full Ca2+ signaling output. (jou2002essentialnonredundantrole pages 4-8)

GO interpretation: supports BP annotations for B cell receptor signaling pathway and intracellular calcium ion mobilization in B cells, with p110δ as a positive regulator/essential component in this context. (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole media 9f8002cf)

2.2 B cell development, activation, proliferation; germinal centers; humoral immunity

In the same p110δ knockout model:
- B cell developmental and compartment defects include reduced mature peripheral B cells and loss of B1 cells. (jou2002essentialnonredundantrole pages 1-2, jou2002essentialnonredundantrole pages 2-4)
- In vitro proliferation: p110δ−/− B cells showed decreased proliferation to anti-CD40 and LPS, and impaired responses to BCR crosslinking; bypass stimulation (PMA+ionomycin) was relatively preserved. (jou2002essentialnonredundantrole pages 4-8)
- Humoral immunity in vivo: reduced baseline serum immunoglobulins and impaired antigen-specific antibody responses—T-independent responses reduced and T-dependent antibody responses absent; germinal center formation impaired/absent by splenic staining after immunization. (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole media 9f8002cf)

Visual evidence from the primary paper (used here as supporting data displays): ELISA immunoglobulin panels, antigen-response panels, absent germinal center staining, and Ca2+ flux traces in wild-type vs p110δ−/− are captured in the retrieved figure crops. (jou2002essentialnonredundantrole media 9f8002cf, jou2002essentialnonredundantrole media 37876baa, jou2002essentialnonredundantrole media 7d2b61ed, jou2002essentialnonredundantrole media 3b78ec57)

GO interpretation: supports BP annotations such as B cell development, B cell activation, B cell proliferation, germinal center formation, and T-dependent humoral immune response. (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole pages 1-2, jou2002essentialnonredundantrole media 9f8002cf)

2.3 Regulatory T cell (Treg) homeostasis and immune tolerance (2024 mechanistic/phenotypic update)

A 2024 conditional mouse model interrogated activated PI3Kδ signaling specifically within Foxp3+ Tregs, clarifying how PI3Kδ activity thresholds control tolerance.

Key recent study (J Immunol, 2024-06; DOI:10.4049/jimmunol.2400032; URL: https://doi.org/10.4049/jimmunol.2400032):
- Treg-restricted activated PI3Kδ (aPIK3CD) increased thymic Treg precursors and peripheral Treg numbers, yet Tregs displayed altered phenotype (e.g., increased PD-1) and reduced competitive fitness. (singh2024activatedpi3kδspecifically pages 1-3)
- Despite increased Treg counts, mice developed chronic inflammation, increased memory/effector CD4+/CD8+ T cells and enhanced IFN-γ secretion, plus spontaneous germinal center responses and broad autoantibody production. (singh2024activatedpi3kδspecifically pages 3-4, singh2024activatedpi3kδspecifically pages 1-3)
- Mechanistic linkage is consistent with PI3K→AKT→FOXO regulation (AKT phosphorylation, FOXO1 nuclear exclusion) affecting Treg stability/function. (singh2024activatedpi3kδspecifically pages 11-13)

GO interpretation: supports BP terms around regulatory T cell homeostasis, immune tolerance/negative regulation of immune response, and regulation of germinal center response/humoral immunity, with an explicit caveat that both loss and gain of PI3Kδ signaling can disrupt tolerance (directionality depends on activity threshold/context). (singh2024activatedpi3kδspecifically pages 1-3, singh2024activatedpi3kδspecifically pages 10-11)

3) Recent developments (prioritize 2023–2024)

3.1 Refined pathway framing for GO: receptor repertoire and downstream readouts

A 2024 review synthesizes receptor contexts and regulatory mechanisms relevant to GO process selection:
- Class IA PI3K (p85–p110δ) is recruited downstream of immune receptors including BCR/TCR/CD28/ICOS/CD19/BAFF-R/CD40, producing PIP3 that drives AKT/mTOR/FOXO-linked programs. (ijspeert2024hyperactivationofthe pages 2-4, ijspeert2024hyperactivationofthe pages 1-2)
- It highlights pathway antagonism by PTEN/SHIP and connects FOXO-regulated transcription (e.g., immune differentiation programs) to PI3K signaling outputs (useful for downstream BP annotations, but requires careful evidence attribution if annotating those distal effects). (ijspeert2024hyperactivationofthe pages 2-4)

Source (Immunotherapy Advances, 2024-11; DOI:10.1093/immadv/ltae009; URL: https://doi.org/10.1093/immadv/ltae009) (ijspeert2024hyperactivationofthe pages 2-4, ijspeert2024hyperactivationofthe pages 1-2)

3.2 Quantitative inhibitor/probe landscape (mechanism, selectivity, and caveats)

Because PI3Kδ is frequently perturbed pharmacologically (both experimentally and clinically), inhibitor properties are directly relevant to interpreting evidence used for GO assertions.

Allosteric vs ATP-competitive PI3Kδ inhibition (2023):
- IOA-244 (roginolisib) behaves as a non–ATP-competitive PI3Kδ inhibitor; kinetic data show minimal ATP Km shift but a strong Vmax reduction in a PIP3 production assay; biochemical IC50 ~19 nM and whole blood IC50 0.28 μM were reported (plus extensive selectivity profiling). (johnson2023ioa244isa pages 6-7, johnson2023ioa244isa pages 13-14)
- Idelalisib shows ATP-competitive behavior (Km shift) and strong PI3Kδ potency (KiNativ PI3Kδ IC50 1.3 nM), but with additional off-target activity and an active metabolite (GS-563117) with its own target spectrum, supporting strong GO curation caveats for pharmacology-derived functional claims. (johnson2023ioa244isa pages 6-7, johnson2023ioa244isa pages 13-14)

Source (Cancer Research Communications, 2023-04; DOI:10.1158/2767-9764.CRC-22-0477; URL: https://doi.org/10.1158/2767-9764.crc-22-0477) (johnson2023ioa244isa pages 6-7, johnson2023ioa244isa pages 13-14)

Leniolisib potency and isoform selectivity (2024):
- Leniolisib is reported as PI3Kδ-selective with IC50 11 nM (PI3Kδ) vs 244 nM (α), 424 nM (β), 2230 nM (γ). (de2024leniolisibanovel pages 1-2, cant2024pi3kδpathwaydysregulation pages 19-20)

Sources: Frontiers in Pharmacology (2024-02; DOI:10.3389/fphar.2024.1337436; URL: https://doi.org/10.3389/fphar.2024.1337436) (de2024leniolisibanovel pages 1-2) and JACI-In Practice (2024-01; DOI:10.1016/j.jaip.2023.09.016; URL: https://doi.org/10.1016/j.jaip.2023.09.016) (cant2024pi3kδpathwaydysregulation pages 19-20)

GO curation implication: inhibitor-based inference is useful for pathway placement (PI3Kδ dependence), but should be down-weighted unless selectivity, concentrations, and metabolites are controlled and accompanied by genetic corroboration. (johnson2023ioa244isa pages 6-7, cant2024pi3kδpathwaydysregulation pages 13-14)

4) Cellular locations and trafficking (GO CC-focused synthesis)

  • Resting state: cytosolic complex of p110δ with p85-family regulatory subunits, with p85 inhibiting catalytic activity until activation signals occur. (ijspeert2024hyperactivationofthe pages 2-4)
  • Activated state: recruitment/translocation of the p85–p110δ complex to plasma membrane via SH2 binding to receptor/adaptor phosphotyrosines, enabling access to PI(4,5)P2 substrate and local PIP3 generation. (ijspeert2024hyperactivationofthe pages 2-4, stokoe2005thephosphoinositide3kinase pages 1-3)

Caveat for CC annotation: Much localization evidence in the retrieved sources is mechanistic/consensus (review synthesis). For strict experimental CC evidence codes, curators may prefer direct imaging/biochemical fractionation papers (not retrieved here in full). (ijspeert2024hyperactivationofthe pages 2-4, stokoe2005thephosphoinositide3kinase pages 1-3)

5) Disease context (only where functionally informative)

Disease genetics mainly reinforce dosage/threshold sensitivity of PI3Kδ signaling in immune function. For example, the Treg-conditional activation study demonstrates that hyperactive PI3Kδ signaling can paradoxically increase Treg numbers while impairing tolerance, emphasizing that GO BP annotations should avoid implying monotonic positive regulation for all downstream immune outcomes. (singh2024activatedpi3kδspecifically pages 1-3)

APDS-focused reviews (2024) frame PI3Kδ hyperactivation as driving excessive AKT/mTOR pathway activity in immune cells and motivating use of selective inhibitors; this is functionally relevant as it highlights pathway readouts (pAKT/pS6) used experimentally. (cant2024pi3kδpathwaydysregulation pages 1-3)

6) GO annotation caveats and curator notes

  1. Isoform redundancy / shared PI3K outputs: Many downstream readouts (e.g., pAKT, pS6) are not isoform-specific, and class I PI3Ks share overlapping functions; p110δ is leukocyte-enriched but not exclusively expressed, so immune-context evidence is strongest for PIK3CD-specific BP claims. (ijspeert2024hyperactivationofthe pages 1-2, cant2024pi3kδpathwaydysregulation pages 1-3)
  2. Pharmacology confounding: PI3Kδ inhibitors differ in mechanism (ATP-competitive vs allosteric), cellular potency vs biochemical potency, off-target profiles, and metabolites; GO assertions based solely on inhibitor phenotypes can be misleading without genetic confirmation. (johnson2023ioa244isa pages 6-7, johnson2023ioa244isa pages 13-14, cant2024pi3kδpathwaydysregulation pages 13-14)
  3. Pathological hyperactivation ≠ physiological role directionality: Hyperactive PI3Kδ in Tregs produces immune dysregulation and autoantibodies despite increased Treg numbers, so annotations should favor neutral process placement (e.g., “involved in”) or carefully qualified regulation terms when direction is context-dependent. (singh2024activatedpi3kδspecifically pages 1-3, singh2024activatedpi3kδspecifically pages 11-13)
  4. Species-to-human transfer: Foundational functional genetics are largely from mouse models (e.g., p110δ knockout). These are highly informative for GO, but annotation should note organism context and confirmability in human systems when possible. (jou2002essentialnonredundantrole pages 4-8)

7) Curator-facing GO mapping table (artifact)

The following table compiles recommended MF/BP/CC terms with evidence summaries and traceable citations.

GO aspect Recommended GO term name Evidence summary (1 line) Key experimental system Best supporting citation IDs
MF phosphatidylinositol-4,5-bisphosphate 3-kinase activity Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD. Cell-free / review synthesis (ijspeert2024hyperactivationofthe pages 1-2, stokoe2005thephosphoinositide3kinase pages 1-3)
MF ATP binding PI3Kδ catalytic activity is ATP-dependent; inhibitor kinetic studies distinguish ATP-competitive idelalisib from non-ATP-competitive IOA-244, reinforcing ATP use at the catalytic site. Cell-free biochemical assays (johnson2023ioa244isa pages 6-7, cant2024pi3kδpathwaydysregulation pages 19-20)
CC class IA phosphatidylinositol 3-kinase complex p110δ forms a class IA heterodimer with p85-family regulatory subunits, with p85 both stabilizing and inhibiting the catalytic subunit in resting cells. Human / review synthesis (ijspeert2024hyperactivationofthe pages 2-4, stokoe2005thephosphoinositide3kinase pages 1-3, berglund2024modulatingthepi3k pages 8-8)
CC plasma membrane recruitment Upon receptor phosphotyrosine signaling, SH2-containing p85 recruits the p85-p110δ complex to the plasma membrane where phosphoinositide substrates reside. Human / review synthesis (ijspeert2024hyperactivationofthe pages 2-4, ijspeert2024hyperactivationofthe pages 1-2, stokoe2005thephosphoinositide3kinase pages 1-3)
BP phosphatidylinositol 3-kinase signaling PI3Kδ-generated PIP3 recruits and activates AKT-linked signaling modules controlling downstream immune-cell responses. Human / mouse / review synthesis (ijspeert2024hyperactivationofthe pages 2-4, ijspeert2024hyperactivationofthe pages 1-2)
BP B cell receptor signaling pathway Genetic loss of p110δ causes a specific BCR signaling defect, indicating a nonredundant positive role downstream of the BCR/CD19 axis. Mouse knockout (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole pages 8-10, jou2002essentialnonredundantrole pages 1-2)
BP intracellular calcium ion mobilization Anti-IgM-induced Ca2+ mobilization in p110δ-deficient B cells is reduced to about 25% of wild type, supporting a role in BCR-triggered Ca2+ signaling. Mouse knockout (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole media 9f8002cf)
BP B cell development p110δ deficiency reduces mature peripheral B cells, causes a developmental block and loss of B1 cells, supporting annotation to B-cell developmental processes. Mouse knockout (jou2002essentialnonredundantrole pages 1-2, jou2002essentialnonredundantrole pages 2-4)
BP B cell activation p110δ-deficient B cells show impaired responses to BCR ligation and reduced activation-associated functional outputs. Mouse knockout (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole pages 2-4)
BP B cell proliferation Splenic p110δ-deficient B cells proliferate poorly in response to anti-IgM, anti-CD40 and LPS, while bypass stimulation is relatively preserved. Mouse knockout (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole pages 2-4)
BP germinal center formation Immunized p110δ-deficient mice fail to form splenic germinal centers, demonstrating a requirement for PI3Kδ in this humoral immune process. Mouse knockout (jou2002essentialnonredundantrole pages 1-2, jou2002essentialnonredundantrole media 9f8002cf)
BP T-dependent humoral immune response T-dependent antibody responses are absent in p110δ-deficient mice, with severe defects also seen for TI responses, supporting a role in antibody production pathways. Mouse knockout (jou2002essentialnonredundantrole pages 4-8, jou2002essentialnonredundantrole media 9f8002cf)
BP AKT signaling / positive regulation of TOR signaling Recent reviews and APDS-related studies place PI3Kδ upstream of AKT, mTORC1/S6 and FOXO regulation; pS6 elevation is used as a downstream readout of pathway activation. Human patients / mouse models (ijspeert2024hyperactivationofthe pages 2-4, nguyen2023humanpik3r1mutations pages 24-25, singh2024activatedpi3kδspecifically pages 11-13)
BP regulatory T cell homeostasis Balanced PI3Kδ activity is required in Tregs: hyperactive PI3Kδ increases Treg numbers but reduces fitness and functional stability, whereas insufficient signaling also impairs tolerance. Mouse conditional GOF / review synthesis (singh2024activatedpi3kδspecifically pages 3-4, singh2024activatedpi3kδspecifically pages 11-13, singh2024activatedpi3kδspecifically pages 1-3)
BP immune tolerance / negative regulation of immune response Treg-restricted activated PI3Kδ drives chronic inflammation, elevated IFN-γ, increased Tfh/GC responses and broad autoantibody production, indicating loss of tolerance when PI3Kδ is dysregulated. Mouse conditional GOF (singh2024activatedpi3kδspecifically pages 3-4, singh2024activatedpi3kδspecifically pages 10-11, singh2024activatedpi3kδspecifically pages 1-3)
BP caveat: isoform redundancy and context dependence Some PI3K outputs can be shared with other class I isoforms; p110δ is leukocyte-enriched but not absolutely exclusive, so annotations should favor immune-context evidence over broad generic signaling claims. Curation note (ijspeert2024hyperactivationofthe pages 1-2, wright2024theimportanceof pages 4-6, cant2024pi3kδpathwaydysregulation pages 1-3)
BP caveat: inhibitor-based evidence can be confounded PI3Kδ inhibitors differ in selectivity, mechanism and metabolites (e.g., ATP-competitive vs noncompetitive; off-target active metabolites), so pharmacology alone should not be over-weighted for direct GO assignment. Curation note / cell-free and cellular pharmacology (johnson2023ioa244isa pages 6-7, de2024leniolisibanovel pages 2-4, cant2024pi3kδpathwaydysregulation pages 13-14, johnson2023ioa244isa pages 15-16)

Table: This table summarizes high-confidence, curator-facing GO annotation suggestions for human PIK3CD/p110δ, mapped to the strongest experimental evidence retrieved in this session. It highlights core molecular function, complex/localization, immune signaling processes, and key curation caveats.

8) Key references with publication dates and URLs (subset)

  • Jou ST et al. Molecular and Cellular Biology (2002-12). “Essential, Nonredundant Role for the Phosphoinositide 3-Kinase p110δ in Signaling by the B-Cell Receptor Complex.” DOI:10.1128/MCB.22.24.8580-8591.2002. https://doi.org/10.1128/mcb.22.24.8580-8591.2002 (jou2002essentialnonredundantrole pages 4-8)
  • IJspeert H et al. Immunotherapy Advances (2024-11). DOI:10.1093/immadv/ltae009. https://doi.org/10.1093/immadv/ltae009 (ijspeert2024hyperactivationofthe pages 2-4)
  • Singh AK et al. Journal of Immunology (2024-06). DOI:10.4049/jimmunol.2400032. https://doi.org/10.4049/jimmunol.2400032 (singh2024activatedpi3kδspecifically pages 1-3)
  • Cant AJ et al. J Allergy Clin Immunol: In Practice (2024-01). DOI:10.1016/j.jaip.2023.09.016. https://doi.org/10.1016/j.jaip.2023.09.016 (cant2024pi3kδpathwaydysregulation pages 19-20)
  • Johnson Z et al. Cancer Research Communications (2023-04). DOI:10.1158/2767-9764.CRC-22-0477. https://doi.org/10.1158/2767-9764.crc-22-0477 (johnson2023ioa244isa pages 6-7)
  • De SK. Frontiers in Pharmacology (2024-02). DOI:10.3389/fphar.2024.1337436. https://doi.org/10.3389/fphar.2024.1337436 (de2024leniolisibanovel pages 1-2)

References

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  15. (singh2024activatedpi3kδspecifically pages 10-11): Akhilesh K. Singh, Fahd Al Qureshah, Travis Drow, Baidong Hou, and David J. Rawlings. Activated pi3kδ specifically perturbs mouse regulatory t cell homeostasis and function leading to immune dysregulation. Journal of immunology, 213:135-147, Jun 2024. URL: https://doi.org/10.4049/jimmunol.2400032, doi:10.4049/jimmunol.2400032. This article has 8 citations and is from a domain leading peer-reviewed journal.

  16. (johnson2023ioa244isa pages 13-14): Zoë Johnson, Chiara Tarantelli, Elisa Civanelli, Luciano Cascione, Filippo Spriano, Amy Fraser, Pritom Shah, Tyzoon Nomanbhoy, Sara Napoli, Andrea Rinaldi, Karolina Niewola-Staszkowska, Michael Lahn, Dominique Perrin, Mathias Wenes, Denis Migliorini, Francesco Bertoni, Lars van der Veen, and Giusy Di Conza. Ioa-244 is a non–atp-competitive, highly selective, tolerable pi3k delta inhibitor that targets solid tumors and breaks immune tolerance. Cancer Research Communications, 3:576-591, Apr 2023. URL: https://doi.org/10.1158/2767-9764.crc-22-0477, doi:10.1158/2767-9764.crc-22-0477. This article has 33 citations and is from a peer-reviewed journal.

  17. (de2024leniolisibanovel pages 1-2): Surya K. De. Leniolisib: a novel treatment for activated phosphoinositide-3 kinase delta syndrome. Frontiers in Pharmacology, Feb 2024. URL: https://doi.org/10.3389/fphar.2024.1337436, doi:10.3389/fphar.2024.1337436. This article has 12 citations.

  18. (cant2024pi3kδpathwaydysregulation pages 19-20): Andrew J. Cant, Anita Chandra, Ewen Munro, V. Koneti Rao, and Carrie L. Lucas. Pi3kδ pathway dysregulation and unique features of its inhibition by leniolisib in activated pi3kδ syndrome and beyond. The Journal of Allergy and Clinical Immunology: In Practice, 12:69-78, Jan 2024. URL: https://doi.org/10.1016/j.jaip.2023.09.016, doi:10.1016/j.jaip.2023.09.016. This article has 34 citations.

  19. (cant2024pi3kδpathwaydysregulation pages 13-14): Andrew J. Cant, Anita Chandra, Ewen Munro, V. Koneti Rao, and Carrie L. Lucas. Pi3kδ pathway dysregulation and unique features of its inhibition by leniolisib in activated pi3kδ syndrome and beyond. The Journal of Allergy and Clinical Immunology: In Practice, 12:69-78, Jan 2024. URL: https://doi.org/10.1016/j.jaip.2023.09.016, doi:10.1016/j.jaip.2023.09.016. This article has 34 citations.

  20. (cant2024pi3kδpathwaydysregulation pages 1-3): Andrew J. Cant, Anita Chandra, Ewen Munro, V. Koneti Rao, and Carrie L. Lucas. Pi3kδ pathway dysregulation and unique features of its inhibition by leniolisib in activated pi3kδ syndrome and beyond. The Journal of Allergy and Clinical Immunology: In Practice, 12:69-78, Jan 2024. URL: https://doi.org/10.1016/j.jaip.2023.09.016, doi:10.1016/j.jaip.2023.09.016. This article has 34 citations.

  21. (berglund2024modulatingthepi3k pages 8-8): Lucinda J. Berglund. Modulating the pi3k signalling pathway in activated pi3k delta syndrome: a clinical perspective. Journal of Clinical Immunology, Dec 2024. URL: https://doi.org/10.1007/s10875-023-01626-0, doi:10.1007/s10875-023-01626-0. This article has 20 citations and is from a domain leading peer-reviewed journal.

  22. (jou2002essentialnonredundantrole pages 8-10): Shiann-Tarng Jou, Nick Carpino, Yutaka Takahashi, Roland Piekorz, Jyh-Rong Chao, Neena Carpino, Demin Wang, and James N. Ihle. Essential, nonredundant role for the phosphoinositide 3-kinase p110δ in signaling by the b-cell receptor complex. Molecular and Cellular Biology, 22:8580-8591, Dec 2002. URL: https://doi.org/10.1128/mcb.22.24.8580-8591.2002, doi:10.1128/mcb.22.24.8580-8591.2002. This article has 480 citations and is from a domain leading peer-reviewed journal.

  23. (nguyen2023humanpik3r1mutations pages 24-25): Tina Nguyen, Anthony Lau, Julia Bier, Kristen C. Cooke, Helen Lenthall, Stephanie Ruiz-Diaz, Danielle T. Avery, Henry Brigden, David Zahra, William A Sewell, Luke Droney, Satoshi Okada, Takaki Asano, Hassan Abolhassani, Zahra Chavoshzadeh, Roshini S. Abraham, Nipunie Rajapakse, Eric W. Klee, Joseph A. Church, Andrew Williams, Melanie Wong, Christoph Burkhart, Gulbu Uzel, David R. Croucher, David E. James, Cindy S. Ma, Robert Brink, Stuart G. Tangye, and Elissa K. Deenick. Human pik3r1 mutations disrupt lymphocyte differentiation to cause activated pi3kδ syndrome 2. The Journal of Experimental Medicine, Mar 2023. URL: https://doi.org/10.1084/jem.20221020, doi:10.1084/jem.20221020. This article has 32 citations.

  24. (wright2024theimportanceof pages 4-6): Brock Wright, Samuel King, and Cenk Suphioglu. The importance of phosphoinositide 3-kinase in neuroinflammation. International Journal of Molecular Sciences, 25:11638, Oct 2024. URL: https://doi.org/10.3390/ijms252111638, doi:10.3390/ijms252111638. This article has 43 citations.

  25. (de2024leniolisibanovel pages 2-4): Surya K. De. Leniolisib: a novel treatment for activated phosphoinositide-3 kinase delta syndrome. Frontiers in Pharmacology, Feb 2024. URL: https://doi.org/10.3389/fphar.2024.1337436, doi:10.3389/fphar.2024.1337436. This article has 12 citations.

  26. (johnson2023ioa244isa pages 15-16): Zoë Johnson, Chiara Tarantelli, Elisa Civanelli, Luciano Cascione, Filippo Spriano, Amy Fraser, Pritom Shah, Tyzoon Nomanbhoy, Sara Napoli, Andrea Rinaldi, Karolina Niewola-Staszkowska, Michael Lahn, Dominique Perrin, Mathias Wenes, Denis Migliorini, Francesco Bertoni, Lars van der Veen, and Giusy Di Conza. Ioa-244 is a non–atp-competitive, highly selective, tolerable pi3k delta inhibitor that targets solid tumors and breaks immune tolerance. Cancer Research Communications, 3:576-591, Apr 2023. URL: https://doi.org/10.1158/2767-9764.crc-22-0477, doi:10.1158/2767-9764.crc-22-0477. This article has 33 citations and is from a peer-reviewed journal.

Citations

  1. ijspeert2024hyperactivationofthe pages 2-4
  2. jou2002essentialnonredundantrole pages 4-8
  3. de2024leniolisibanovel pages 1-2
  4. ijspeert2024hyperactivationofthe pages 1-2
  5. jou2002essentialnonredundantrole pages 1-2
  6. jou2002essentialnonredundantrole pages 2-4
  7. jou2002essentialnonredundantrole pages 8-10
  8. wright2024theimportanceof pages 4-6
  9. de2024leniolisibanovel pages 2-4
  10. https://www.uniprot.org/uniprotkb/O00329/
  11. https://doi.org/10.1128/mcb.22.24.8580-8591.2002
  12. https://doi.org/10.4049/jimmunol.2400032
  13. https://doi.org/10.1093/immadv/ltae009
  14. https://doi.org/10.1158/2767-9764.crc-22-0477
  15. https://doi.org/10.3389/fphar.2024.1337436
  16. https://doi.org/10.1016/j.jaip.2023.09.016
  17. https://doi.org/10.1093/immadv/ltae009,
  18. https://doi.org/10.1017/s1462399405009361,
  19. https://doi.org/10.1158/2767-9764.crc-22-0477,
  20. https://doi.org/10.1128/mcb.22.24.8580-8591.2002,
  21. https://doi.org/10.4049/jimmunol.2400032,
  22. https://doi.org/10.3389/fphar.2024.1337436,
  23. https://doi.org/10.1016/j.jaip.2023.09.016,
  24. https://doi.org/10.1007/s10875-023-01626-0,
  25. https://doi.org/10.1084/jem.20221020,
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📚 Additional Documentation

Notes

(PIK3CD-notes.md)

PIK3CD curation notes

2026-05-12 Falcon integration

Generated Falcon deep research at PIK3CD-deep-research-falcon.md and used it with
UniProt plus cached publications to complete the initialized GO review.

Core synthesis: PIK3CD encodes p110delta, a leukocyte-enriched class IA PI3K
catalytic subunit. The central molecular function is PI(4,5)P2 3-kinase
activity producing PIP3 in p85-family regulatory complexes at receptor-activated
membranes. Falcon summarizes this as: [file:human/PIK3CD/PIK3CD-deep-research-falcon.md
"PIK3CD encodes the catalytic subunit p110δ of class IA phosphoinositide
3-kinase (PI3Kδ)
, a lipid kinase that produces PI(3,4,5)P3 (PIP3) at
membranes downstream of receptor signaling in immune cells, particularly in
lymphocytes."] Direct biochemical work also reports that recombinant p110delta
phosphorylates phosphatidylinositol and associates with p85 PMID:9235916.

The most informative process terms are PI3K/AKT signaling plus immune receptor
contexts, especially BCR, TCR, and CD28. Falcon frames the receptor context as
[file:human/PIK3CD/PIK3CD-deep-research-falcon.md "In immune cells, class IA PI3K
(including p110δ) propagates signaling downstream of BCR, TCR, CD28, ICOS,
CD19, BAFF-R, CD40
"] and UniProt separately records BCR and TCR requirements
[file:human/PIK3CD/PIK3CD-uniprot.txt "Required for B-cell receptor (BCR) signaling."]
[file:human/PIK3CD/PIK3CD-uniprot.txt "Required for T-cell receptor (TCR) signaling."].

Broad immune, chemotaxis, endothelial migration, angiogenesis, mast-cell,
neutrophil, NK-cell, and cytokine-production annotations were retained as
non-core where supported. The main evidence is that PI3Kdelta participates in
multiple leukocyte outputs PMID:20940048 and myeloid
activities PMID:20940048.

Several terms were deliberately modified or marked over-annotated:

  • Generic PI3K complex was modified to class IA PI3K complex.
  • Generic kinase/transferase/nucleotide-binding terms were narrowed toward ATP
    binding or PI(4,5)P2 3-kinase activity.
  • PI3P biosynthetic process was modified because that term implies class
    III/VPS34-like biology; PIK3CD is primarily a PIP3-producing class IA kinase.
  • Protein binding was marked over-annotated because complex membership and lipid
    kinase activity are the informative annotations.
  • Protein phosphorylation was modified because PMID:9113989 supports lipid
    substrate specificity and says p110delta does not phosphorylate p85
    PMID:9113989.

📄 View Raw YAML

id: O00329
gene_symbol: PIK3CD
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: 'PIK3CD encodes p110delta, the leukocyte-enriched catalytic subunit of class
  IA phosphoinositide 3-kinase delta. In p85-family regulatory complexes, p110delta phosphorylates
  membrane phosphoinositides, especially PI(4,5)P2, to generate PIP3 downstream of immune
  receptors including BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40, Fc receptors, and cytokine/growth-factor
  receptors. The core curatable function is PIP3-producing lipid kinase activity in PI3K/AKT
  immune receptor signaling; broad immune phenotypes, chemotaxis, angiogenesis, and migration
  annotations are supported contextual outputs rather than the core molecular function.'
alternative_products:
- name: 1 (p110-delta)
  id: O00329-1
- name: 2 (p37-delta)
  id: O00329-2
  sequence_note: VSP_044409, VSP_044410
existing_annotations:
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0016477
    label: cell migration
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported cell-migration role in specific leukocyte and glioma contexts,
      but non-core relative to lipid kinase signaling.
    action: KEEP_AS_NON_CORE
    reason: PIK3CD knockdown decreases glioma-cell migration and PI3Kdelta also affects
      leukocyte migration; these are downstream context-specific outputs rather than the
      core function.
    supported_by:
    - reference_id: PMID:22079609
      supporting_text: Interestingly, knockdown of p110δ decreased the cell migration
        and invasion ability of all GBM cell lines tested.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
- term:
    id: GO:0005942
    label: phosphatidylinositol 3-kinase complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: The complex assignment is valid but should use the more specific class IA
      phosphatidylinositol 3-kinase complex term.
    action: MODIFY
    reason: PIK3CD is not just any PI3K-complex component; it is the p110delta catalytic
      subunit of class IA p85-family regulatory complexes. GO:0005943 captures the
      correct complex subtype.
    proposed_replacement_terms:
    - id: GO:0005943
      label: phosphatidylinositol 3-kinase complex, class IA
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
- term:
    id: GO:0043491
    label: phosphatidylinositol 3-kinase/protein kinase B signal transduction
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated
      PIP3.
    action: ACCEPT
    reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This
      pathway term captures the central signaling output of PI3Kdelta even when the
      initiating receptor or cell type differs.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: '**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide
        3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes
        downstream of receptor signaling in immune cells, particularly in lymphocytes.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
- term:
    id: GO:0036092
    label: phosphatidylinositol-3-phosphate biosynthetic process
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: The PI3P biosynthetic-process term is too specific for a class
      III/VPS34-like product and is not the best process term for PIK3CD.
    action: MODIFY
    reason: PIK3CD/p110delta primarily generates PIP3 from PI(4,5)P2 in class IA
      receptor signaling. A broader phosphatidylinositol phosphate biosynthetic process
      term better reflects the current GO vocabulary without implying class III
      PI3P-centered biology.
    proposed_replacement_terms:
    - id: GO:0046854
      label: phosphatidylinositol phosphate biosynthetic process
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
    - reference_id: Reactome:R-HSA-389158
      supporting_text: Upon binding to CD28, the PI3K enzyme catalyzes the
        phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate
        phosphatidylinositol 3,4,5-trisphosphate (PIP3).
- term:
    id: GO:0048015
    label: phosphatidylinositol-mediated signaling
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: The phosphatidylinositol-mediated signaling term is correct but too broad
      for PIK3CD.
    action: MODIFY
    reason: PIK3CD is specifically a class IA PIP3-producing PI3K that feeds PI3K/AKT
      receptor signaling, so the more specific PI3K/AKT signal-transduction term is
      preferred.
    proposed_replacement_terms:
    - id: GO:0043491
      label: phosphatidylinositol 3-kinase/protein kinase B signal transduction
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: '**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide
        3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes
        downstream of receptor signaling in immune cells, particularly in lymphocytes.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0016303
    label: 1-phosphatidylinositol-3-kinase activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Core molecular function as a phosphatidylinositol 3-kinase catalytic
      subunit.
    action: ACCEPT
    reason: This parent PI3K activity term is valid for p110delta, although GO:0046934
      is the most specific MF term for its canonical PIP2-to-PIP3 reaction.
    supported_by:
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
- term:
    id: GO:0035005
    label: 1-phosphatidylinositol-4-phosphate 3-kinase activity
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: Supported phosphoinositide 3-kinase substrate activity, but PI4P
      phosphorylation is not the primary curatable core activity for PIK3CD.
    action: KEEP_AS_NON_CORE
    reason: Class I PI3Kdelta can act on phosphorylated phosphoinositides, and Reactome
      includes PIK3CD complexes in PI4P-to-PI(3,4)P2 reactions. The canonical core
      activity remains PI(4,5)P2-to-PIP3.
    supported_by:
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
    - reference_id: Reactome:R-HSA-1676109
      supporting_text: These complexes along with phosphatidylinositol-4-phosphate
        3-kinase C2 domain-containing subunits alpha (PIK3C2A), beta (PIK3C2B), and
        gamma (PIK3C2G) phosphorylate phosphatidylinositol 4-phosphate (PI4P) to
        phosphatidylinositol 3,4-bisphosphate (PI(3,4)P2).
- term:
    id: GO:0000166
    label: nucleotide binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: The nucleotide-binding annotation is too generic for a lipid kinase and
      should be narrowed to ATP binding.
    action: MODIFY
    reason: PIK3CD catalysis uses ATP; the broad nucleotide-binding term loses the
      catalytic context and is less informative than GO:0005524 ATP binding or the
      catalytic PI(4,5)P2 3-kinase MF.
    proposed_replacement_terms:
    - id: GO:0005524
      label: ATP binding
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
- term:
    id: GO:0002250
    label: adaptive immune response
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: Supported adaptive-immune output, but this is a systems-level consequence
      of PI3Kdelta immune receptor signaling rather than the core molecular function.
    action: KEEP_AS_NON_CORE
    reason: Human disease genetics and leukocyte studies support a role in adaptive
      immunity, but the core function should remain PIP3-producing class IA PI3K
      signaling.
    supported_by:
    - reference_id: PMID:27616589
      supporting_text: Here, we review the roles of PI3Kδ in adaptive immunity, describe
        the clinical manifestations and mechanisms of disease in APDS and highlight new
        insights into PI3Kδ gleaned from these patients, as well as implications of
        these findings for clinical therapy.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0002376
    label: immune system process
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: Correct directionally but too broad to be useful for PIK3CD curation.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD has immune functions, but GO:0002376 is a very broad parent term.
      More informative annotations are BCR/TCR signaling, PI3K/AKT signaling, and
      specific leukocyte activation/migration processes.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0002443
    label: leukocyte mediated immunity
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Supported leukocyte/immune response involvement, but non-core and broad
      relative to receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: PIK3CD is leukocyte-enriched and affects immune responses, yet this broad
      immune-process term should not define the core function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
    - reference_id: PMID:27616589
      supporting_text: Here, we review the roles of PI3Kδ in adaptive immunity, describe
        the clinical manifestations and mechanisms of disease in APDS and highlight new
        insights into PI3Kδ gleaned from these patients, as well as implications of
        these findings for clinical therapy.
- term:
    id: GO:0005524
    label: ATP binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: ATP binding is valid for the catalytic kinase domain, but it is generic
      relative to the core lipid kinase activity.
    action: KEEP_AS_NON_CORE
    reason: ATP is required for PI3Kdelta catalysis, yet ATP binding alone is not a
      specific description of the gene product function.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005943
    label: phosphatidylinositol 3-kinase complex, class IA
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Correct class IA PI3K complex annotation for p110delta/p85-family
      regulatory assemblies.
    action: ACCEPT
    reason: This is the most specific existing CC term for PIK3CD complex membership and
      is supported by ComplexPortal entries and synthesis of the class IA p110delta-p85
      regulatory complex.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: Reactome:R-HSA-2316434
      supporting_text: In unstimulated cells, PI3K class IA exists as an inactive
        heterodimer of a p85 regulatory subunit (encoded by PIK3R1, PIK3R2 or PIK3R3)
        and a p110 catalytic subunit (encoded by PIK3CA, PIK3CB or PIK3CD).
- term:
    id: GO:0006629
    label: lipid metabolic process
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: The lipid metabolic process term is directionally correct but too broad for
      PIK3CD.
    action: MODIFY
    reason: PIK3CD is specifically a phosphoinositide lipid kinase that produces
      3-phosphoinositides/PIP3 in signaling contexts; phosphatidylinositol phosphate
      biosynthesis is the more informative same-aspect process replacement, while the
      specific PI(4,5)P2 3-kinase molecular function is handled separately.
    proposed_replacement_terms:
    - id: GO:0046854
      label: phosphatidylinositol phosphate biosynthetic process
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0006935
    label: chemotaxis
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: The generic chemotaxis annotation should be narrowed to the specific
      leukocyte chemotaxis processes supported for PIK3CD.
    action: MODIFY
    reason: The evidence supports T-cell, B-cell, neutrophil, and mast-cell chemotaxis
      contexts rather than chemotaxis as a broad parent term.
    proposed_replacement_terms:
    - id: GO:0010818
      label: T cell chemotaxis
    - id: GO:0035754
      label: B cell chemotaxis
    - id: GO:0030593
      label: neutrophil chemotaxis
    - id: GO:0002551
      label: mast cell chemotaxis
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0006954
    label: inflammatory response
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: Supported inflammatory-response involvement, but it is a downstream
      physiological output of PI3Kdelta activity.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta disruption alters inflammatory responses in vivo and PI3K lipid
      messengers control leukocyte signaling, but inflammation is a non-core
      phenotype/process relative to lipid kinase signaling.
    supported_by:
    - reference_id: PMID:17290298
      supporting_text: Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second
        messengers that control an array of intracellular signalling pathways that are
        known to have important roles in leukocytes.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0007166
    label: cell surface receptor signaling pathway
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: The broad cell-surface receptor signaling annotation should be narrowed to
      the immune receptor signaling pathways where PIK3CD has strong support.
    action: MODIFY
    reason: PIK3CD acts downstream of immune receptors such as BCR, TCR, and CD28. Those
      terms are more informative and better supported than the generic cell-surface
      receptor signaling parent.
    proposed_replacement_terms:
    - id: GO:0050853
      label: B cell receptor signaling pathway
    - id: GO:0050852
      label: T cell receptor signaling pathway
    - id: GO:0031295
      label: T cell costimulation
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for B-cell receptor (BCR) signaling.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for T-cell receptor (TCR) signaling.
- term:
    id: GO:0010595
    label: positive regulation of endothelial cell migration
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Supported endothelial/angiogenesis context, but non-core and
      tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
    action: KEEP_AS_NON_CORE
    reason: Cultured endothelial-cell work supports VEGF-induced Akt activation,
      proliferation, migration, tube formation, and retinal angiogenesis. This is a real
      contextual role, not the primary leukocyte-enriched core function.
    supported_by:
    - reference_id: PMID:31915155
      supporting_text: Using genetic and pharmacological approaches, we show that p110δ
        activity in cultured ECs controls Akt activation, cell proliferation, migration,
        and tube formation induced by vascular endothelial growth factor, basic
        fibroblast growth factor, and epidermal growth factor.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
- term:
    id: GO:0010628
    label: positive regulation of gene expression
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Over-annotation to positive regulation of gene expression. The available
      PIK3CD evidence supports upstream PI3K/AKT signaling more directly than this
      distal transcriptional-output term.
    action: MARK_AS_OVER_ANNOTATED
    reason: Gene-expression changes can occur downstream of PI3K/AKT/FOXO signaling, but
      the evidence supports this as a distal pathway output requiring careful
      attribution rather than a direct core PIK3CD function. This broad distal term
      should not be retained as a core annotation.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: It highlights pathway antagonism by PTEN/SHIP and connects
        FOXO-regulated transcription (e.g., immune differentiation programs) to PI3K
        signaling outputs (useful for downstream BP annotations, but requires careful
        evidence attribution if annotating those distal effects).
- term:
    id: GO:0016301
    label: kinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: The generic enzyme-activity annotation is valid only as a distant parent
      and should be replaced by the specific lipid kinase activity.
    action: MODIFY
    reason: PIK3CD is not merely a generic kinase/transferase; the evidence supports
      phosphoinositide 3-kinase activity, especially PI(4,5)P2 3-kinase activity.
    proposed_replacement_terms:
    - id: GO:0046934
      label: 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
- term:
    id: GO:0016303
    label: 1-phosphatidylinositol-3-kinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: Core molecular function as a phosphatidylinositol 3-kinase catalytic
      subunit.
    action: ACCEPT
    reason: This parent PI3K activity term is valid for p110delta, although GO:0046934
      is the most specific MF term for its canonical PIP2-to-PIP3 reaction.
    supported_by:
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
- term:
    id: GO:0016740
    label: transferase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: The generic enzyme-activity annotation is valid only as a distant parent
      and should be replaced by the specific lipid kinase activity.
    action: MODIFY
    reason: PIK3CD is not merely a generic kinase/transferase; the evidence supports
      phosphoinositide 3-kinase activity, especially PI(4,5)P2 3-kinase activity.
    proposed_replacement_terms:
    - id: GO:0046934
      label: 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
- term:
    id: GO:0022603
    label: regulation of anatomical structure morphogenesis
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Over-annotation to broad developmental, morphogenesis, or adhesion
      regulation terms.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but
      these broad regulation terms over-generalize downstream effects and obscure the
      better-supported PI3Kdelta receptor-signaling biology.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0030154
    label: cell differentiation
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: The generic cell differentiation annotation should be narrowed to the
      specific leukocyte differentiation processes supported for PIK3CD.
    action: MODIFY
    reason: The evidence supports B-cell, T-cell, NK-cell, and mast-cell differentiation
      contexts rather than undifferentiated cell differentiation as a generic parent.
    proposed_replacement_terms:
    - id: GO:0030183
      label: B cell differentiation
    - id: GO:0030217
      label: T cell differentiation
    - id: GO:0001779
      label: natural killer cell differentiation
    - id: GO:0060374
      label: mast cell differentiation
    supported_by:
    - reference_id: PMID:20200404
      supporting_text: Thus, we provide novel evidence that p110gamma and p110delta have
        overlapping and cell-extrinsic roles in the development, peripheral maintenance,
        and function of B cells.
    - reference_id: PMID:17371229
      supporting_text: In addition, p110delta regulates the differentiation of
        peripheral Th (helper T-cells) towards the Th1 and Th2 lineages.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
- term:
    id: GO:0030155
    label: regulation of cell adhesion
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Over-annotation to broad developmental, morphogenesis, or adhesion
      regulation terms.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but
      these broad regulation terms over-generalize downstream effects and obscure the
      better-supported PI3Kdelta receptor-signaling biology.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0033031
    label: positive regulation of neutrophil apoptotic process
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Supported neutrophil-death/apoptotic-process annotation, but non-core and
      context-dependent.
    action: KEEP_AS_NON_CORE
    reason: FcαRI-triggered neutrophil death requires class IA PI3K signaling in
      inflammatory contexts. This supports the annotation as a non-core immune effector
      process.
    supported_by:
    - reference_id: PMID:25339672
      supporting_text: preactivation with cytokines or TLR agonists in vitro enhanced
        FcαRI-mediated death by additional recruitment of caspase-independent pathways,
        but this required PI3K class IA and MAPK signaling.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0042113
    label: B cell activation
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Supported B-cell activation/function annotation, but downstream of the more
      core BCR signaling role.
    action: KEEP_AS_NON_CORE
    reason: PIK3CD is important for B-cell development and function. B-cell activation
      is real, but BCR signaling and PI3K/AKT signaling are the more precise core
      process annotations.
    supported_by:
    - reference_id: PMID:20200404
      supporting_text: Thus, we provide novel evidence that p110gamma and p110delta have
        overlapping and cell-extrinsic roles in the development, peripheral maintenance,
        and function of B cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for B-cell receptor (BCR) signaling.
- term:
    id: GO:0043491
    label: phosphatidylinositol 3-kinase/protein kinase B signal transduction
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated
      PIP3.
    action: ACCEPT
    reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This
      pathway term captures the central signaling output of PI3Kdelta even when the
      initiating receptor or cell type differs.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: '**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide
        3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes
        downstream of receptor signaling in immune cells, particularly in lymphocytes.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
- term:
    id: GO:0045087
    label: innate immune response
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: Supported innate-immune involvement, but this is a broad non-core
      immune-system output.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta contributes to myeloid and innate leukocyte activities, but the
      precise core function is receptor-linked PIP3 production rather than innate
      immunity as a whole.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
    - reference_id: PMID:17290298
      supporting_text: Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second
        messengers that control an array of intracellular signalling pathways that are
        known to have important roles in leukocytes.
- term:
    id: GO:0046854
    label: phosphatidylinositol phosphate biosynthetic process
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: Supported core process output of PI3Kdelta lipid kinase activity.
    action: ACCEPT
    reason: PIK3CD produces 3-phosphoinositides, especially PIP3, as the biochemical
      product of its class IA lipid kinase activity. This process term is broader than
      an ideal PIP3-biosynthesis term but is correct.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
    - reference_id: Reactome:R-HSA-389158
      supporting_text: Upon binding to CD28, the PI3K enzyme catalyzes the
        phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate
        phosphatidylinositol 3,4,5-trisphosphate (PIP3).
- term:
    id: GO:0046934
    label: 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  review:
    summary: 'Core specific molecular function: p110delta phosphorylates PI(4,5)P2 to generate
      PIP3.'
    action: ACCEPT
    reason: PI(4,5)P2 3-kinase activity is the specific catalytic activity that drives
      PI3Kdelta receptor signaling and PIP3-dependent AKT pathway recruitment.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
    - reference_id: Reactome:R-HSA-389158
      supporting_text: Upon binding to CD28, the PI3K enzyme catalyzes the
        phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate
        phosphatidylinositol 3,4,5-trisphosphate (PIP3).
- term:
    id: GO:0051094
    label: positive regulation of developmental process
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Over-annotation to broad developmental, morphogenesis, or adhesion
      regulation terms.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but
      these broad regulation terms over-generalize downstream effects and obscure the
      better-supported PI3Kdelta receptor-signaling biology.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0051240
    label: positive regulation of multicellular organismal process
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Over-annotation to broad developmental, morphogenesis, or adhesion
      regulation terms.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but
      these broad regulation terms over-generalize downstream effects and obscure the
      better-supported PI3Kdelta receptor-signaling biology.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:2000026
    label: regulation of multicellular organismal development
  evidence_type: IEA
  original_reference_id: GO_REF:0000117
  review:
    summary: Over-annotation to broad developmental, morphogenesis, or adhesion
      regulation terms.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD has specific leukocyte, endothelial, and migration phenotypes, but
      these broad regulation terms over-generalize downstream effects and obscure the
      better-supported PI3Kdelta receptor-signaling biology.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:21827948
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:22020336
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:24165795
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:28514442
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:31031754
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32296183
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:33961781
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:35271311
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:40205054
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: IDA
  original_reference_id: GO_REF:0000052
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32606397
  review:
    summary: Protein binding is an uninformative over-annotation for PIK3CD.
    action: MARK_AS_OVER_ANNOTATED
    reason: PIK3CD does interact with p85-family regulatory subunits and other signaling
      proteins, but GO:0005515 does not capture the meaningful function. The informative
      annotations are class IA PI3K complex membership and phosphoinositide kinase
      activity.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
- term:
    id: GO:0031295
    label: T cell costimulation
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-389356
  review:
    summary: Supported CD28/T-cell costimulation context for PI3Kdelta signaling.
    action: ACCEPT
    reason: CD28 is a direct immune receptor context in which PI3K participates in
      costimulatory signaling and PIP3 generation. This is part of the core
      immune-receptor signaling frame for PIK3CD.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: Reactome:R-HSA-389356
      supporting_text: The cytoplasmic tail of CD28, upon ligand binding, undergoes
        phosphorylation by Src family kinases like LCK and FYN, triggering downstream
        signaling pathways involving PI3K, VAV-1, Tec family kinases, AKT, and other
        adaptor proteins (Sharpe & Freeman 2002; Chen & Flies 2013).
    - reference_id: Reactome:R-HSA-389158
      supporting_text: Upon binding to CD28, the PI3K enzyme catalyzes the
        phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate
        phosphatidylinositol 3,4,5-trisphosphate (PIP3).
- term:
    id: GO:0046934
    label: 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-389158
  review:
    summary: 'Core specific molecular function: p110delta phosphorylates PI(4,5)P2 to generate
      PIP3.'
    action: ACCEPT
    reason: PI(4,5)P2 3-kinase activity is the specific catalytic activity that drives
      PI3Kdelta receptor signaling and PIP3-dependent AKT pathway recruitment.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
    - reference_id: Reactome:R-HSA-389158
      supporting_text: Upon binding to CD28, the PI3K enzyme catalyzes the
        phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate
        phosphatidylinositol 3,4,5-trisphosphate (PIP3).
- term:
    id: GO:0006955
    label: immune response
  evidence_type: NAS
  original_reference_id: PMID:27616589
  review:
    summary: Supported leukocyte/immune response involvement, but non-core and broad
      relative to receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: PIK3CD is leukocyte-enriched and affects immune responses, yet this broad
      immune-process term should not define the core function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
    - reference_id: PMID:27616589
      supporting_text: Here, we review the roles of PI3Kδ in adaptive immunity, describe
        the clinical manifestations and mechanisms of disease in APDS and highlight new
        insights into PI3Kδ gleaned from these patients, as well as implications of
        these findings for clinical therapy.
- term:
    id: GO:0030183
    label: B cell differentiation
  evidence_type: NAS
  original_reference_id: PMID:20200404
  review:
    summary: Supported B-cell differentiation/development role, but non-core relative to
      PI3Kdelta catalytic signaling.
    action: KEEP_AS_NON_CORE
    reason: B-cell developmental phenotypes are well supported, but they are downstream
      organism/cell lineage consequences of PIP3-producing PI3Kdelta signaling.
    supported_by:
    - reference_id: PMID:20200404
      supporting_text: Thus, we provide novel evidence that p110gamma and p110delta have
        overlapping and cell-extrinsic roles in the development, peripheral maintenance,
        and function of B cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for B-cell receptor (BCR) signaling.
- term:
    id: GO:0030217
    label: T cell differentiation
  evidence_type: NAS
  original_reference_id: PMID:17371229
  review:
    summary: Supported T-cell differentiation role, but non-core relative to
      receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: T-cell differentiation is a supported immune-cell outcome of p110delta
      activity, not the core molecular function itself.
    supported_by:
    - reference_id: PMID:17371229
      supporting_text: In addition, p110delta regulates the differentiation of
        peripheral Th (helper T-cells) towards the Th1 and Th2 lineages.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
- term:
    id: GO:0038084
    label: vascular endothelial growth factor signaling pathway
  evidence_type: IGI
  original_reference_id: PMID:31915155
  review:
    summary: Supported endothelial/angiogenesis context, but non-core and
      tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
    action: KEEP_AS_NON_CORE
    reason: Cultured endothelial-cell work supports VEGF-induced Akt activation,
      proliferation, migration, tube formation, and retinal angiogenesis. This is a real
      contextual role, not the primary leukocyte-enriched core function.
    supported_by:
    - reference_id: PMID:31915155
      supporting_text: Using genetic and pharmacological approaches, we show that p110δ
        activity in cultured ECs controls Akt activation, cell proliferation, migration,
        and tube formation induced by vascular endothelial growth factor, basic
        fibroblast growth factor, and epidermal growth factor.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
- term:
    id: GO:0010595
    label: positive regulation of endothelial cell migration
  evidence_type: IGI
  original_reference_id: PMID:31915155
  review:
    summary: Supported endothelial/angiogenesis context, but non-core and
      tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
    action: KEEP_AS_NON_CORE
    reason: Cultured endothelial-cell work supports VEGF-induced Akt activation,
      proliferation, migration, tube formation, and retinal angiogenesis. This is a real
      contextual role, not the primary leukocyte-enriched core function.
    supported_by:
    - reference_id: PMID:31915155
      supporting_text: Using genetic and pharmacological approaches, we show that p110δ
        activity in cultured ECs controls Akt activation, cell proliferation, migration,
        and tube formation induced by vascular endothelial growth factor, basic
        fibroblast growth factor, and epidermal growth factor.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
- term:
    id: GO:0001938
    label: positive regulation of endothelial cell proliferation
  evidence_type: IGI
  original_reference_id: PMID:31915155
  review:
    summary: Supported endothelial/angiogenesis context, but non-core and
      tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
    action: KEEP_AS_NON_CORE
    reason: Cultured endothelial-cell work supports VEGF-induced Akt activation,
      proliferation, migration, tube formation, and retinal angiogenesis. This is a real
      contextual role, not the primary leukocyte-enriched core function.
    supported_by:
    - reference_id: PMID:31915155
      supporting_text: Using genetic and pharmacological approaches, we show that p110δ
        activity in cultured ECs controls Akt activation, cell proliferation, migration,
        and tube formation induced by vascular endothelial growth factor, basic
        fibroblast growth factor, and epidermal growth factor.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
- term:
    id: GO:0043491
    label: phosphatidylinositol 3-kinase/protein kinase B signal transduction
  evidence_type: IGI
  original_reference_id: PMID:31915155
  review:
    summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated
      PIP3.
    action: ACCEPT
    reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This
      pathway term captures the central signaling output of PI3Kdelta even when the
      initiating receptor or cell type differs.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: '**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide
        3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes
        downstream of receptor signaling in immune cells, particularly in lymphocytes.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
- term:
    id: GO:0045766
    label: positive regulation of angiogenesis
  evidence_type: ISS
  original_reference_id: GO_REF:0000024
  review:
    summary: Supported endothelial/angiogenesis context, but non-core and
      tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
    action: KEEP_AS_NON_CORE
    reason: Cultured endothelial-cell work supports VEGF-induced Akt activation,
      proliferation, migration, tube formation, and retinal angiogenesis. This is a real
      contextual role, not the primary leukocyte-enriched core function.
    supported_by:
    - reference_id: PMID:31915155
      supporting_text: Using genetic and pharmacological approaches, we show that p110δ
        activity in cultured ECs controls Akt activation, cell proliferation, migration,
        and tube formation induced by vascular endothelial growth factor, basic
        fibroblast growth factor, and epidermal growth factor.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
- term:
    id: GO:1905278
    label: positive regulation of epithelial tube formation
  evidence_type: IGI
  original_reference_id: PMID:31915155
  review:
    summary: Supported endothelial/angiogenesis context, but non-core and
      tissue/pathology-specific relative to PI3Kdelta immune receptor signaling.
    action: KEEP_AS_NON_CORE
    reason: Cultured endothelial-cell work supports VEGF-induced Akt activation,
      proliferation, migration, tube formation, and retinal angiogenesis. This is a real
      contextual role, not the primary leukocyte-enriched core function.
    supported_by:
    - reference_id: PMID:31915155
      supporting_text: Using genetic and pharmacological approaches, we show that p110δ
        activity in cultured ECs controls Akt activation, cell proliferation, migration,
        and tube formation induced by vascular endothelial growth factor, basic
        fibroblast growth factor, and epidermal growth factor.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
- term:
    id: GO:0033031
    label: positive regulation of neutrophil apoptotic process
  evidence_type: IMP
  original_reference_id: PMID:25339672
  review:
    summary: Supported neutrophil-death/apoptotic-process annotation, but non-core and
      context-dependent.
    action: KEEP_AS_NON_CORE
    reason: FcαRI-triggered neutrophil death requires class IA PI3K signaling in
      inflammatory contexts. This supports the annotation as a non-core immune effector
      process.
    supported_by:
    - reference_id: PMID:25339672
      supporting_text: preactivation with cytokines or TLR agonists in vitro enhanced
        FcαRI-mediated death by additional recruitment of caspase-independent pathways,
        but this required PI3K class IA and MAPK signaling.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0043491
    label: phosphatidylinositol 3-kinase/protein kinase B signal transduction
  evidence_type: IMP
  original_reference_id: PMID:25339672
  review:
    summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated
      PIP3.
    action: ACCEPT
    reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This
      pathway term captures the central signaling output of PI3Kdelta even when the
      initiating receptor or cell type differs.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: '**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide
        3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes
        downstream of receptor signaling in immune cells, particularly in lymphocytes.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
- term:
    id: GO:0001779
    label: natural killer cell differentiation
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported NK-cell differentiation role, but non-core relative to PI3Kdelta
      catalytic signaling.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta participates in NK-cell development and migration, but this is a
      leukocyte-specific cellular outcome rather than the core lipid kinase function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
- term:
    id: GO:0001819
    label: positive regulation of cytokine production
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported cytokine-production role, but non-core and downstream of immune
      receptor signaling.
    action: KEEP_AS_NON_CORE
    reason: Cytokine-production changes are leukocyte outputs of PI3Kdelta signaling,
      not the primary biochemical function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for T-cell receptor (TCR) signaling.
- term:
    id: GO:0002250
    label: adaptive immune response
  evidence_type: TAS
  original_reference_id: PMID:17290298
  review:
    summary: Supported adaptive-immune output, but this is a systems-level consequence
      of PI3Kdelta immune receptor signaling rather than the core molecular function.
    action: KEEP_AS_NON_CORE
    reason: Human disease genetics and leukocyte studies support a role in adaptive
      immunity, but the core function should remain PIP3-producing class IA PI3K
      signaling.
    supported_by:
    - reference_id: PMID:27616589
      supporting_text: Here, we review the roles of PI3Kδ in adaptive immunity, describe
        the clinical manifestations and mechanisms of disease in APDS and highlight new
        insights into PI3Kδ gleaned from these patients, as well as implications of
        these findings for clinical therapy.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0002551
    label: mast cell chemotaxis
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core
      relative to receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta affects migration of multiple leukocyte types, but these are
      cell-type-specific outputs of the core PIP3-generating immune signaling function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0002679
    label: respiratory burst involved in defense response
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported neutrophil respiratory-burst role, but non-core relative to the
      catalytic PI3Kdelta signaling function.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta contributes to neutrophil respiratory burst as a myeloid effector
      output, but this is not the core molecular function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0006954
    label: inflammatory response
  evidence_type: TAS
  original_reference_id: PMID:17290298
  review:
    summary: Supported inflammatory-response involvement, but it is a downstream
      physiological output of PI3Kdelta activity.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta disruption alters inflammatory responses in vivo and PI3K lipid
      messengers control leukocyte signaling, but inflammation is a non-core
      phenotype/process relative to lipid kinase signaling.
    supported_by:
    - reference_id: PMID:17290298
      supporting_text: Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second
        messengers that control an array of intracellular signalling pathways that are
        known to have important roles in leukocytes.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0006954
    label: inflammatory response
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported inflammatory-response involvement, but it is a downstream
      physiological output of PI3Kdelta activity.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta disruption alters inflammatory responses in vivo and PI3K lipid
      messengers control leukocyte signaling, but inflammation is a non-core
      phenotype/process relative to lipid kinase signaling.
    supported_by:
    - reference_id: PMID:17290298
      supporting_text: Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second
        messengers that control an array of intracellular signalling pathways that are
        known to have important roles in leukocytes.
    - reference_id: PMID:20940048
      supporting_text: As a result of the broad effects of PI3Kδ in leukocyte functions,
        the disruption of PI3Kδ expression or activity leads to decreased inflammatory
        and immune responses in vivo.
- term:
    id: GO:0010818
    label: T cell chemotaxis
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core
      relative to receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta affects migration of multiple leukocyte types, but these are
      cell-type-specific outputs of the core PIP3-generating immune signaling function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0016303
    label: 1-phosphatidylinositol-3-kinase activity
  evidence_type: TAS
  original_reference_id: PMID:17290298
  review:
    summary: Core molecular function as a phosphatidylinositol 3-kinase catalytic
      subunit.
    action: ACCEPT
    reason: This parent PI3K activity term is valid for p110delta, although GO:0046934
      is the most specific MF term for its canonical PIP2-to-PIP3 reaction.
    supported_by:
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
- term:
    id: GO:0030101
    label: natural killer cell activation
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported NK-cell activation context, but non-core relative to
      receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: NK-cell activation is a supported immune output; the central curatable
      function remains PI3Kdelta PIP3 production in leukocyte signaling.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
- term:
    id: GO:0030217
    label: T cell differentiation
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported T-cell differentiation role, but non-core relative to
      receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: T-cell differentiation is a supported immune-cell outcome of p110delta
      activity, not the core molecular function itself.
    supported_by:
    - reference_id: PMID:17371229
      supporting_text: In addition, p110delta regulates the differentiation of
        peripheral Th (helper T-cells) towards the Th1 and Th2 lineages.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
- term:
    id: GO:0030593
    label: neutrophil chemotaxis
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core
      relative to receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta affects migration of multiple leukocyte types, but these are
      cell-type-specific outputs of the core PIP3-generating immune signaling function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0035747
    label: natural killer cell chemotaxis
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core
      relative to receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta affects migration of multiple leukocyte types, but these are
      cell-type-specific outputs of the core PIP3-generating immune signaling function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0035754
    label: B cell chemotaxis
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core
      relative to receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta affects migration of multiple leukocyte types, but these are
      cell-type-specific outputs of the core PIP3-generating immune signaling function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0042110
    label: T cell activation
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported T-cell activation/function annotation, but downstream of the more
      core TCR/CD28 signaling role.
    action: KEEP_AS_NON_CORE
    reason: PIK3CD contributes to T-cell development, activation, and migration. The
      T-cell activation process is supported but is a cellular outcome of the core
      TCR/CD28 PI3K signaling function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for T-cell receptor (TCR) signaling.
- term:
    id: GO:0042113
    label: B cell activation
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported B-cell activation/function annotation, but downstream of the more
      core BCR signaling role.
    action: KEEP_AS_NON_CORE
    reason: PIK3CD is important for B-cell development and function. B-cell activation
      is real, but BCR signaling and PI3K/AKT signaling are the more precise core
      process annotations.
    supported_by:
    - reference_id: PMID:20200404
      supporting_text: Thus, we provide novel evidence that p110gamma and p110delta have
        overlapping and cell-extrinsic roles in the development, peripheral maintenance,
        and function of B cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for B-cell receptor (BCR) signaling.
- term:
    id: GO:0043303
    label: mast cell degranulation
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported mast-cell degranulation role, but non-core relative to the
      catalytic PI3Kdelta function.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta contributes to mast-cell degranulation, but this is a
      cell-type-specific effector output rather than the core molecular function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0043491
    label: phosphatidylinositol 3-kinase/protein kinase B signal transduction
  evidence_type: TAS
  original_reference_id: PMID:17290298
  review:
    summary: Supported PI3K/AKT signaling annotation downstream of PIK3CD-generated
      PIP3.
    action: ACCEPT
    reason: PIP3 produced by p110delta recruits AKT-linked signaling modules. This
      pathway term captures the central signaling output of PI3Kdelta even when the
      initiating receptor or cell type differs.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: '**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide
        3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes
        downstream of receptor signaling in immune cells, particularly in lymphocytes.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ is a lipid kinase of the PI3K class IA family involved in
        early signaling events of leukocytes responding to a wide variety of stimuli.
- term:
    id: GO:0045087
    label: innate immune response
  evidence_type: TAS
  original_reference_id: PMID:17290298
  review:
    summary: Supported innate-immune involvement, but this is a broad non-core
      immune-system output.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta contributes to myeloid and innate leukocyte activities, but the
      precise core function is receptor-linked PIP3 production rather than innate
      immunity as a whole.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
    - reference_id: PMID:17290298
      supporting_text: Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second
        messengers that control an array of intracellular signalling pathways that are
        known to have important roles in leukocytes.
- term:
    id: GO:0045087
    label: innate immune response
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported innate-immune involvement, but this is a broad non-core
      immune-system output.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta contributes to myeloid and innate leukocyte activities, but the
      precise core function is receptor-linked PIP3 production rather than innate
      immunity as a whole.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
    - reference_id: PMID:17290298
      supporting_text: Phosphoinositide 3-kinases (PI3Ks) generate lipid-based second
        messengers that control an array of intracellular signalling pathways that are
        known to have important roles in leukocytes.
- term:
    id: GO:0050852
    label: T cell receptor signaling pathway
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported TCR signaling role for PI3Kdelta.
    action: ACCEPT
    reason: UniProt and the literature synthesis identify p110delta as required for TCR
      signaling, making this one of the core immune receptor signaling processes for
      PIK3CD.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for T-cell receptor (TCR) signaling.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
- term:
    id: GO:0050853
    label: B cell receptor signaling pathway
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported BCR signaling role for PI3Kdelta.
    action: ACCEPT
    reason: p110delta is required for BCR signaling and B-cell functional outputs; this
      is one of the strongest process annotations for PIK3CD.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: Required for B-cell receptor (BCR) signaling.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
    - reference_id: PMID:20200404
      supporting_text: Thus, we provide novel evidence that p110gamma and p110delta have
        overlapping and cell-extrinsic roles in the development, peripheral maintenance,
        and function of B cells.
- term:
    id: GO:0060374
    label: mast cell differentiation
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported mast-cell differentiation role, but non-core relative to the
      catalytic PI3Kdelta function.
    action: KEEP_AS_NON_CORE
    reason: Mast-cell maturation/differentiation is a supported leukocyte-cell output of
      PI3Kdelta signaling, not the core molecular activity.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0072672
    label: neutrophil extravasation
  evidence_type: TAS
  original_reference_id: PMID:20940048
  review:
    summary: Supported leukocyte migration/chemotaxis/extravasation role, but non-core
      relative to receptor-proximal PI3Kdelta signaling.
    action: KEEP_AS_NON_CORE
    reason: PI3Kdelta affects migration of multiple leukocyte types, but these are
      cell-type-specific outputs of the core PIP3-generating immune signaling function.
    supported_by:
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
    - reference_id: PMID:20940048
      supporting_text: The role of PI3Kδ in myeloid cell activities, such as
        inflammation driven cell infiltration, neutrophil oxidative burst, immune
        complex mediated macrophage activation, as well as mast cell maturation and
        degranulation, has been well illustrated in various studies.
- term:
    id: GO:0010628
    label: positive regulation of gene expression
  evidence_type: IMP
  original_reference_id: PMID:22079609
  review:
    summary: Over-annotation to positive regulation of gene expression. The available
      PIK3CD evidence supports upstream PI3K/AKT signaling more directly than this
      distal transcriptional-output term.
    action: MARK_AS_OVER_ANNOTATED
    reason: Gene-expression changes can occur downstream of PI3K/AKT/FOXO signaling, but
      the evidence supports this as a distal pathway output requiring careful
      attribution rather than a direct core PIK3CD function. This broad distal term
      should not be retained as a core annotation.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Many downstream readouts (e.g., pAKT, pS6) are not
        isoform-specific, and class I PI3Ks share overlapping functions; p110δ is
        leukocyte-enriched but not exclusively expressed, so immune-context evidence is
        strongest for PIK3CD-specific BP claims.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: It highlights pathway antagonism by PTEN/SHIP and connects
        FOXO-regulated transcription (e.g., immune differentiation programs) to PI3K
        signaling outputs (useful for downstream BP annotations, but requires careful
        evidence attribution if annotating those distal effects).
- term:
    id: GO:0030335
    label: positive regulation of cell migration
  evidence_type: IMP
  original_reference_id: PMID:22079609
  review:
    summary: Supported cell-migration role in specific leukocyte and glioma contexts,
      but non-core relative to lipid kinase signaling.
    action: KEEP_AS_NON_CORE
    reason: PIK3CD knockdown decreases glioma-cell migration and PI3Kdelta also affects
      leukocyte migration; these are downstream context-specific outputs rather than the
      core function.
    supported_by:
    - reference_id: PMID:22079609
      supporting_text: Interestingly, knockdown of p110δ decreased the cell migration
        and invasion ability of all GBM cell lines tested.
    - reference_id: PMID:20940048
      supporting_text: PI3Kδ participates in the development, activation and migration
        of T cells and NK cells.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-1676048
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-1676109
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-9012657
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-9021627
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-9027275
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-9606887
  review:
    summary: Supported cytoplasmic or cytosolic localization, but this is the
      resting/general pool rather than the most informative activated signaling site.
    action: KEEP_AS_NON_CORE
    reason: UniProt records cytoplasmic localization and the deep research report
      describes resting p110delta-p85 complexes as cytosolic. The functionally decisive
      event is receptor-driven membrane recruitment, so cytoplasm/cytosol should not be
      treated as the core location.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269|PubMed:22020336}.'
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2045911
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2076220
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2316434
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-2400009
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-388830
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-388832
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-389158
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-508247
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-879917
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-8854905
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-912627
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-914182
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005886
    label: plasma membrane
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-9606887
  review:
    summary: Supported core activated-site localization. PI3Kdelta is recruited to
      plasma-membrane receptor/adaptor complexes where its phosphoinositide substrates
      reside.
    action: ACCEPT
    reason: Membrane recruitment is central to class IA PI3Kdelta activity because PIP2
      substrate is membrane localized and receptor phosphotyrosine signals recruit the
      p85-p110delta complex to the plasma membrane.
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Upon receptor phosphotyrosine signaling, SH2-containing p85
        recruits the p85-p110δ complex to the plasma membrane where phosphoinositide
        substrates reside.
    - reference_id: Reactome:R-HSA-1676048
      supporting_text: At the plasma membrane, phosphatidylinositol-4,5-bisphosphate
        3-kinase catalytic subunits form complexes with regulatory subunits.
- term:
    id: GO:0005942
    label: phosphatidylinositol 3-kinase complex
  evidence_type: NAS
  original_reference_id: PMID:9113989
  review:
    summary: The complex assignment is valid but should use the more specific class IA
      phosphatidylinositol 3-kinase complex term.
    action: MODIFY
    reason: PIK3CD is not just any PI3K-complex component; it is the p110delta catalytic
      subunit of class IA p85-family regulatory complexes. GO:0005943 captures the
      correct complex subtype.
    proposed_replacement_terms:
    - id: GO:0005943
      label: phosphatidylinositol 3-kinase complex, class IA
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
- term:
    id: GO:0005942
    label: phosphatidylinositol 3-kinase complex
  evidence_type: NAS
  original_reference_id: PMID:9235916
  review:
    summary: The complex assignment is valid but should use the more specific class IA
      phosphatidylinositol 3-kinase complex term.
    action: MODIFY
    reason: PIK3CD is not just any PI3K-complex component; it is the p110delta catalytic
      subunit of class IA p85-family regulatory complexes. GO:0005943 captures the
      correct complex subtype.
    proposed_replacement_terms:
    - id: GO:0005943
      label: phosphatidylinositol 3-kinase complex, class IA
    supported_by:
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: p110δ forms a class IA heterodimer with p85-family regulatory
        subunits, with p85 both stabilizing and inhibiting the catalytic subunit in
        resting cells.
    - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
      supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
        class IA, p110delta/p85alpha.
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
- term:
    id: GO:0006468
    label: protein phosphorylation
  evidence_type: NAS
  original_reference_id: PMID:9113989
  review:
    summary: Over-annotation to protein phosphorylation. PIK3CD is primarily a
      phosphoinositide lipid kinase, not a protein kinase.
    action: MODIFY
    reason: PMID:9113989 reports lipid substrate specificity and explicitly
      distinguishes p110delta from p110alpha by noting that it does not phosphorylate
      p85, despite intrinsic autophosphorylation. The same-aspect replacement should be
      lipid phosphorylation rather than general protein phosphorylation; the specific
      PI(4,5)P2 3-kinase molecular function is handled separately.
    proposed_replacement_terms:
    - id: GO:0046834
      label: lipid phosphorylation
    supported_by:
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
    - reference_id: PMID:9113989
      supporting_text: Unlike p110alpha, p110delta does not phosphorylate p85 but
        instead harbors an intrinsic autophosphorylation capacity.
- term:
    id: GO:0007165
    label: signal transduction
  evidence_type: NAS
  original_reference_id: PMID:9113989
  review:
    summary: The generic signal-transduction annotation should be narrowed to PI3K/AKT
      and immune receptor signaling.
    action: MODIFY
    reason: PIK3CD participates in signaling by generating PIP3 downstream of receptor
      activation. The generic signal transduction parent obscures the specific PI3K/AKT,
      BCR, and TCR pathways supported by the evidence.
    proposed_replacement_terms:
    - id: GO:0043491
      label: phosphatidylinositol 3-kinase/protein kinase B signal transduction
    - id: GO:0050853
      label: B cell receptor signaling pathway
    - id: GO:0050852
      label: T cell receptor signaling pathway
    supported_by:
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
        signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and
        related receptor/adaptor systems), framing the major immune-cell BP terms
        relevant for PIK3CD.
- term:
    id: GO:0016303
    label: 1-phosphatidylinositol-3-kinase activity
  evidence_type: NAS
  original_reference_id: PMID:9235916
  review:
    summary: Core molecular function as a phosphatidylinositol 3-kinase catalytic
      subunit.
    action: ACCEPT
    reason: This parent PI3K activity term is valid for p110delta, although GO:0046934
      is the most specific MF term for its canonical PIP2-to-PIP3 reaction.
    supported_by:
    - reference_id: PMID:9235916
      supporting_text: Recombinant p110delta phosphorylates phosphatidylinositol and
        coimmunoprecipitates with p85.
    - reference_id: PMID:9113989
      supporting_text: p110delta displays a broad phosphoinositide lipid substrate
        specificity and interacts with SH2/SH3 domain-containing p85 adaptor proteins
        and with GTP-bound Ras.
    - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
      supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
        PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000024
  title: Manual transfer of experimentally-verified manual GO annotation data to
    orthologs by curator judgment of sequence similarity
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000043
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location
    vocabulary mapping, accompanied by conservative changes to GO terms applied by
    UniProt
  findings: []
- id: GO_REF:0000052
  title: Gene Ontology annotation based on curation of immunofluorescence data
  findings: []
- id: GO_REF:0000117
  title: Electronic Gene Ontology annotations created by ARBA machine learning models
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:17290298
  title: 'PI3K delta and PI3K gamma: partners in crime in inflammation in rheumatoid arthritis
    and beyond?'
  findings: []
- id: PMID:17371229
  title: The PI3K p110delta controls T-cell development, differentiation and regulation.
  findings: []
- id: PMID:20200404
  title: The catalytic PI3K isoforms p110gamma and p110delta contribute to B cell
    development and maintenance, transformation, and proliferation.
  findings: []
- id: PMID:20940048
  title: Phosphoinositide 3-kinase delta (PI3Kδ) in leukocyte signaling and function.
  findings: []
- id: PMID:21827948
  title: Dynamics of the phosphoinositide 3-kinase p110δ interaction with p85α and
    membranes reveals aspects of regulation distinct from p110α.
  findings: []
- id: PMID:22020336
  title: p37δ is a new isoform of PI3K p110δ that increases cell proliferation and is
    overexpressed in tumors.
  findings: []
- id: PMID:22079609
  title: The catalytic phosphoinositol 3-kinase isoform p110δ is required for glioma
    cell migration and invasion.
  findings: []
- id: PMID:24165795
  title: Dominant-activating germline mutations in the gene encoding the PI(3)K
    catalytic subunit p110δ result in T cell senescence and human immunodeficiency.
  findings: []
- id: PMID:25339672
  title: Human IgA Fc receptor FcαRI (CD89) triggers different forms of neutrophil death
    depending on the inflammatory microenvironment.
  findings: []
- id: PMID:27616589
  title: PI3Kδ and primary immunodeficiencies.
  findings: []
- id: PMID:28514442
  title: Architecture of the human interactome defines protein communities and disease
    networks.
  findings: []
- id: PMID:31031754
  title: 'Case Study: Mechanism for Increased Follicular Helper T Cell Development in Activated
    PI3K Delta Syndrome.'
  findings: []
- id: PMID:31915155
  title: PI3Kδ as a Novel Therapeutic Target in Pathological Angiogenesis.
  findings: []
- id: PMID:32296183
  title: A reference map of the human binary protein interactome.
  findings: []
- id: PMID:32606397
  title: PI3K activation is enhanced by FOXM1D binding to p110 and p85 subunits.
  findings: []
- id: PMID:33961781
  title: Dual proteome-scale networks reveal cell-specific remodeling of the human
    interactome.
  findings: []
- id: PMID:35271311
  title: 'OpenCell: Endogenous tagging for the cartography of human cellular organization.'
  findings: []
- id: PMID:40205054
  title: Multimodal cell maps as a foundation for structural and functional genomics.
  findings: []
- id: PMID:9113989
  title: P110delta, a novel phosphoinositide 3-kinase in leukocytes.
  findings: []
- id: PMID:9235916
  title: p110delta, a novel phosphatidylinositol 3-kinase catalytic subunit that
    associates with p85 and is expressed predominantly in leukocytes.
  findings: []
- id: Reactome:R-HSA-1676048
  title: PI(4,5)P2 is phosphorylated to PI(3,4,5)P3 by PIK3C[1] at the plasma membrane
  findings: []
- id: Reactome:R-HSA-1676109
  title: PI4P is phosphorylated to PI(3,4)P2 by PI3K3C[2] at the plasma membrane
  findings: []
- id: Reactome:R-HSA-2045911
  title: BCAP Signalosome phosphorylates PI(4,5)P2 forming PI(3,4,5)P3
  findings: []
- id: Reactome:R-HSA-2076220
  title: CD19 Signalosome phosphorylates PI(4,5)P2 forming PI(3,4,5)P3
  findings: []
- id: Reactome:R-HSA-2316434
  title: PI3K phosphorylates PIP2 to PIP3
  findings: []
- id: Reactome:R-HSA-2400009
  title: PI3K inhibitors block PI3K catalytic activity
  findings: []
- id: Reactome:R-HSA-388830
  title: PI3K binds ICOS
  findings: []
- id: Reactome:R-HSA-388832
  title: PI3K binds CD28
  findings: []
- id: Reactome:R-HSA-389158
  title: CD28 bound PI3K phosphorylates PIP2 to PIP3
  findings: []
- id: Reactome:R-HSA-389356
  title: Co-stimulation by CD28
  findings: []
- id: Reactome:R-HSA-508247
  title: Gab2 binds the p85 subunit of Class 1A PI3 kinases
  findings: []
- id: Reactome:R-HSA-879917
  title: CBL, GRB2, FYN and PI3K p85 subunit are constitutively associated
  findings: []
- id: Reactome:R-HSA-8854905
  title: p-5Y-GAB in the RET-GRB2-GAB complexes binds p85-PI3K
  findings: []
- id: Reactome:R-HSA-9012657
  title: EPO:phospho-EPOR:phospho-JAK2:LYN:phospho-IRS2 binds PI3K
  findings: []
- id: Reactome:R-HSA-9021627
  title: EPOR-associated PI3K phosphorylates PIP2 to PIP3
  findings: []
- id: Reactome:R-HSA-9027275
  title: EPO:phospho-EPOR:phospho-JAK2:LYN:IRS2:phospho-GAB1 binds PI3K
  findings: []
- id: Reactome:R-HSA-912627
  title: CBL ubiquitinates PI3K
  findings: []
- id: Reactome:R-HSA-914182
  title: 14-3-3 zeta binding allows recruitment of PI3K
  findings: []
- id: Reactome:R-HSA-9606887
  title: p-CD19:VAV binds PI3K and GRB2
  findings: []
- id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
  title: Falcon deep research report on PIK3CD
  findings: []
- id: file:human/PIK3CD/PIK3CD-uniprot.txt
  title: UniProtKB record for PIK3CD
  findings: []
core_functions:
- molecular_function:
    id: GO:0046934
    label: 1-phosphatidylinositol-4,5-bisphosphate 3-kinase activity
  description: PIK3CD/p110delta is the leukocyte-enriched class IA PI3K catalytic
    subunit that forms p85-family regulatory complexes and generates PIP3 from PI(4,5)P2
    at receptor-activated membranes.
  directly_involved_in:
  - id: GO:0043491
    label: phosphatidylinositol 3-kinase/protein kinase B signal transduction
  - id: GO:0050853
    label: B cell receptor signaling pathway
  - id: GO:0050852
    label: T cell receptor signaling pathway
  - id: GO:0031295
    label: T cell costimulation
  locations:
  - id: GO:0005886
    label: plasma membrane
  in_complex:
    id: GO:0005943
    label: phosphatidylinositol 3-kinase complex, class IA
  supported_by:
  - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
    supporting_text: '**PIK3CD** encodes the catalytic subunit **p110δ** of **class IA phosphoinositide
      3-kinase (PI3Kδ)**, a lipid kinase that produces **PI(3,4,5)P3 (PIP3)** at membranes
      downstream of receptor signaling in immune cells, particularly in lymphocytes.'
  - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
    supporting_text: Class I/IA PI3Ks, including p110δ, phosphorylate PI(4,5)P2 to
      PI(3,4,5)P3; this is the core enzymatic activity of PIK3CD.
  - reference_id: file:human/PIK3CD/PIK3CD-deep-research-falcon.md
    supporting_text: In immune cells, class IA PI3K (including p110δ) propagates
      signaling downstream of **BCR, TCR, CD28, ICOS, CD19, BAFF-R, CD40** (and related
      receptor/adaptor systems), framing the major immune-cell BP terms relevant for
      PIK3CD.
  - reference_id: Reactome:R-HSA-389158
    supporting_text: Upon binding to CD28, the PI3K enzyme catalyzes the phosphorylation
      of phosphatidylinositol 4,5-bisphosphate (PIP2) to generate phosphatidylinositol
      3,4,5-trisphosphate (PIP3).
  - reference_id: file:human/PIK3CD/PIK3CD-uniprot.txt
    supporting_text: ComplexPortal; CPX-5983; Phosphatidylinositol 3-kinase complex
      class IA, p110delta/p85alpha.
proposed_new_terms: []
suggested_questions:
- question: Which PIK3CD-dependent leukocyte migration, neutrophil death, and
    endothelial angiogenesis annotations remain physiologically relevant in human
    primary cells after controlling for class I PI3K isoform redundancy and inhibitor
    selectivity?
- question: Should GO include a more specific biological-process term for class I
    PI3K-mediated PI(3,4,5)P3 biosynthesis to avoid using PI3P-centered or overly broad
    phosphatidylinositol phosphate biosynthetic process terms for PIK3CD?
suggested_experiments:
- description: Use isoform-selective genetic rescue in human primary B and T cells to
    separate PIK3CD-specific BCR, TCR, and CD28 signaling outputs from overlapping
    PIK3CA/PIK3CB/PIK3CG class I PI3K activity.
  experiment_type: primary-cell genetic rescue and phosphoprotein/PIP3 readout
- description: Measure PI(4,5)P2-to-PIP3 and PI4P-to-PI(3,4)P2 product formation for
    p110delta-p85 complexes under matched in vitro and membrane-recruitment conditions
    to clarify whether PI4P kinase annotations should remain non-core.
  experiment_type: lipid kinase substrate-specificity assay