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The gene FGFR4 (UniProt accession P22455) encodes Fibroblast Growth Factor Receptor 4 in Homo sapiens (human), a receptor tyrosine kinase (EC 2.7.10.1) belonging to the protein kinase superfamily and specifically to the Tyr protein kinase family (nguyen2024thecomplexityand pages 6-8, he2025fgfraberrationsin pages 2-4). This receptor is correctly identified and matches the UniProt annotation, confirming it contains immunoglobulin-like domains (Ig-like_dom, Ig_I-set) and FGF receptor family domains (FGF_rcpt_fam), consistent with the provided protein family information.
FGFR4 is a single-pass transmembrane receptor tyrosine kinase with a highly conserved modular architecture shared across the FGFR family (he2025fgfraberrationsin pages 2-4, chioni2021biologicalsignificanceand pages 2-5). The receptor consists of three principal structural regions: an extracellular ligand-binding region, a single transmembrane helix, and an intracellular tyrosine kinase domain (nguyen2024thecomplexityand pages 6-8, ferguson2021fibroblastgrowthfactor pages 2-3, astolfi2020theemergingrole pages 1-3).
| Domain/Region | Location | Key Features | Functional Role |
|---|---|---|---|
| Signal peptide / precursor segment | Extreme N-terminus; removed during maturation in the secretory pathway | Directs nascent FGFR4 into the endoplasmic-reticulum membrane and supports biosynthetic processing as a type-I single-pass membrane protein | Enables extracellular presentation of the ligand-binding region and delivery of mature FGFR4 to the cell surface |
| Immunoglobulin-like domain D1 (IgI) | N-terminal extracellular region | Contains the N-glycosylation site Asn112; together with the acid box, forms an autoinhibitory module rather than the principal ligand-binding surface (nguyen2024thecomplexityand pages 6-8, he2025fgfraberrationsin pages 2-4) | Limits inappropriate receptor activation and helps maintain FGFR4 in a quiescent state; glycosylation influences receptor folding, processing, and localization (he2025fgfraberrationsin pages 2-4, phillips2022glycosylationoffgfr4 pages 6-8) |
| Acid box | Extracellular linker between D1 and D2 | Acidic, serine-rich sequence characteristic of FGFR-family receptors (he2025fgfraberrationsin pages 2-4, nguyen2024thecomplexityand pages 4-6) | Cooperates with D1 in receptor autoinhibition and modulates accessibility of the D2–D3 ligand-binding module (he2025fgfraberrationsin pages 2-4, astolfi2020theemergingrole pages 1-3) |
| Immunoglobulin-like domain D2 (IgII) | Central extracellular region | Contains Asn258, a reported N-glycosylation site; contributes substantially to the FGF-binding interface and coreceptor interactions (nguyen2024thecomplexityand pages 6-8, he2025fgfraberrationsin pages 2-4) | Directly participates in FGF recognition and formation of ligand–receptor–coreceptor complexes with heparan sulfate or Klotho proteins (he2025fgfraberrationsin pages 2-4, chioni2021biologicalsignificanceand pages 2-5) |
| Immunoglobulin-like domain D3 (IgIII; FGFR4 c-type configuration) | Membrane-proximal extracellular region | Contains reported N-glycosylation sites Asn290, Asn311, and Asn322; combines with D2 to form the principal ligand-binding pocket. Unlike FGFR1–3, FGFR4 has one principal IgIII configuration rather than alternatively spliced b/c isoforms (nguyen2024thecomplexityand pages 6-8, chioni2021biologicalsignificanceand pages 2-5) | Major determinant of ligand selectivity, including the structurally favored interaction with FGF19; glycosylation contributes to receptor maturation, surface delivery, processing, and cytoprotective signaling (edirisinghe2024decodingfgffgfrsignaling pages 14-15, phillips2022glycosylationoffgfr4 pages 6-8) |
| Transmembrane domain | Single α-helical segment spanning the plasma membrane | Connects the extracellular ligand-binding module to the cytoplasmic signaling region; receptor activation organizes FGFR4 dimers across the membrane (he2025fgfraberrationsin pages 2-4, chioni2021biologicalsignificanceand pages 2-5) | Transmits ligand- and coreceptor-induced conformational changes across the membrane, bringing intracellular kinase domains into an activation-competent arrangement |
| Juxtamembrane region | Cytoplasmic segment immediately C-terminal to the transmembrane helix | Provides binding interfaces for membrane-associated adaptor proteins, notably FRS2 and CRK/CRKL (ferguson2021fibroblastgrowthfactor pages 2-3) | Couples activated FGFR4 to FRS2-dependent RAS–MAPK and PI3K–AKT signaling and helps organize receptor-proximal signaling complexes (ferguson2021fibroblastgrowthfactor pages 2-3, ferguson2021fibroblastgrowthfactor pages 3-5) |
| Tyrosine-kinase domain—TK1 and TK2 lobes | Intracellular catalytic region | Split protein-kinase architecture containing the ATP-binding pocket and activation loop; ligand-induced dimerization causes trans-autophosphorylation. The hinge-region Cys552 is uncommon among FGFR paralogues and can be covalently targeted by FGFR4-selective inhibitors (nguyen2024thecomplexityand pages 6-8, he2025fgfraberrationsin pages 2-4, miranda2020developmentofa pages 1-2) | Catalyzes ATP-dependent transfer of phosphate to tyrosine residues on FGFR4 and downstream substrates such as FRS2α and PLCγ, initiating MAPK, PI3K–AKT, PLCγ–PKC/Ca²⁺, and STAT signaling (xie2020fibroblastgrowthfactor pages 3-4, xie2020fibroblastgrowthfactor pages 4-5, ferguson2021fibroblastgrowthfactor pages 3-5) |
| C-terminal tail | Intracellular region following the kinase domain | Flexible regulatory segment containing phosphorylation-dependent interaction sites; forms part of the signaling platform created by activated FGFR4 (chioni2021biologicalsignificanceand pages 2-5, ferguson2021fibroblastgrowthfactor pages 2-3) | Supports recruitment and regulation of downstream effectors and contributes to the magnitude, duration, and routing of FGFR4 signaling, including signaling from plasma-membrane and endosomal compartments (szybowska2021negativeregulationof pages 6-7, szybowska2021negativeregulationof pages 4-6) |
Table: This table maps the extracellular, transmembrane, and intracellular regions of human FGFR4 to their principal structural features and functions. It highlights experimentally relevant glycosylation sites and the kinase-domain Cys552 residue exploited by FGFR4-selective covalent inhibitors.
The extracellular region comprises three immunoglobulin-like domains (D1, D2, and D3) and an acid box, an acidic serine-rich sequence positioned between D1 and D2 (he2025fgfraberrationsin pages 2-4, nguyen2024thecomplexityand pages 4-6). The D1 domain and acid box contribute to receptor autoinhibition, maintaining FGFR4 in a quiescent state prior to ligand binding (he2025fgfraberrationsin pages 2-4, astolfi2020theemergingrole pages 1-3). The D2 and D3 domains form the principal FGF-binding interface and are essential for ligand recognition and coreceptor interactions (he2025fgfraberrationsin pages 2-4, chioni2021biologicalsignificanceand pages 2-5). Unlike FGFR1–3, which undergo alternative splicing to generate "b" and "c" isoforms of the D3/IgIII domain, FGFR4 exists predominantly as a single c-type isoform, providing it with distinct ligand-binding specificity (nguyen2024thecomplexityand pages 6-8, chioni2021biologicalsignificanceand pages 2-5).
A distinctive structural feature of FGFR4 is the presence of cysteine 552 (Cys552) in the kinase-domain hinge region, which is not conserved in FGFR1–3 (nguyen2024thecomplexityand pages 6-8, miranda2020developmentofa pages 1-2). This residue has proven invaluable for therapeutic development, as it can be covalently targeted by highly selective FGFR4 inhibitors, enabling exquisite receptor selectivity over other FGFR family members (nguyen2024thecomplexityand pages 6-8, miranda2020developmentofa pages 1-2, schwarz2024developmentofhighly pages 52-55). The extracellular domains also contain multiple N-glycosylation sites (Asn112 in D1, Asn258 in D2, and Asn290, Asn311, Asn322 in D3) that influence receptor folding, trafficking, processing, and signaling (nguyen2024thecomplexityand pages 6-8, phillips2022glycosylationoffgfr4 pages 6-8).
The intracellular region contains a juxtamembrane segment that provides binding sites for adaptor proteins such as FRS2 and CRK/CRKL, followed by a split tyrosine kinase domain (TK1 and TK2 lobes) and a C-terminal regulatory tail (ferguson2021fibroblastgrowthfactor pages 2-3, chioni2021biologicalsignificanceand pages 2-5). Upon ligand-induced receptor dimerization, the kinase domains undergo trans-autophosphorylation, creating docking sites for downstream signaling effectors and activating the catalytic activity required for substrate phosphorylation (xie2020fibroblastgrowthfactor pages 3-4, xie2020fibroblastgrowthfactor pages 4-5, ferguson2021fibroblastgrowthfactor pages 3-5).
As a receptor tyrosine kinase, FGFR4's primary molecular function is to bind extracellular FGF ligands and transduce this signal across the plasma membrane through tyrosine phosphorylation of intracellular substrates (he2025fgfraberrationsin pages 2-4, liu2026fgffamilyin pages 3-4, xie2020fibroblastgrowthfactor pages 3-4).
FGFR4 exhibits broad ligand-binding capacity, interacting with multiple FGF family members, but shows particularly high affinity and specificity for FGF19 (FGF15 in mice) (ferguson2021fibroblastgrowthfactor pages 2-3, edirisinghe2024decodingfgffgfrsignaling pages 14-15). This specificity is structurally encoded by complementary features at the FGF19–FGFR4 interface, including the extended β1 strand of FGF19 and the longer βC′–βE loop of FGFR4 (edirisinghe2024decodingfgffgfrsignaling pages 14-15).
| FGF ligand | Subfamily | Binding characteristics with FGFR4 | Coreceptor requirements | Primary biological context |
|---|---|---|---|---|
| FGF1 | FGF1 subfamily; paracrine/canonical | Promiscuous ligand capable of activating all classical FGFRs, including FGFR4 (ferguson2021fibroblastgrowthfactor pages 2-3, nguyen2024thecomplexityand pages 2-4) | Heparan-sulfate proteoglycan (HSPG) or heparin stabilizes the signaling complex | Broad mitogenic, survival, repair, and cancer-associated signaling |
| FGF2 | FGF1 subfamily; paracrine/canonical | Broad-specificity ligand reported to bind FGFR4, although FGFR1 is commonly its dominant receptor (ferguson2021fibroblastgrowthfactor pages 2-3, nguyen2024thecomplexityand pages 2-4, farooq2021theroleof pages 5-6) | HSPG or heparin | Angiogenesis, proliferation, tissue repair, and development |
| FGF4 | FGF4 subfamily; paracrine/canonical | Established FGFR4 ligand; also activates several FGFR c isoforms (ferguson2021fibroblastgrowthfactor pages 2-3, ferguson2021fibroblastgrowthfactor pages 8-9, nguyen2024thecomplexityand pages 2-4) | HSPG or heparin | Embryonic development, tissue growth, hepatic protection, and regeneration |
| FGF5 | FGF4 subfamily; paracrine/canonical | Reported at the subfamily level to bind FGFR4; FGFR4-specific quantitative affinity is not well established (ferguson2021fibroblastgrowthfactor pages 2-3, ferguson2021fibroblastgrowthfactor pages 8-9) | HSPG or heparin | Developmental and tissue-growth signaling, including hair-cycle regulation |
| FGF6 | FGF4 subfamily; paracrine/canonical | Recognized FGFR4 ligand, with functional signaling through FGFR4 reported in multiple contexts (ferguson2021fibroblastgrowthfactor pages 2-3, ferguson2021fibroblastgrowthfactor pages 8-9, farooq2021theroleof pages 5-6) | HSPG or heparin | Skeletal-muscle development and regeneration; context-dependent cancer signaling |
| FGF8 | FGF8 subfamily; paracrine/canonical | FGF8 splice variants can activate FGFR4; strong binding has been reported for a two-Ig-domain FGFR4 variant, making isoform and experimental context important (ferguson2021fibroblastgrowthfactor pages 8-9, farooq2021theroleof pages 5-6) | HSPG or heparin | Embryonic patterning, organogenesis, and neural development |
| FGF9 | FGF9 subfamily; paracrine/canonical | Reported FGFR4 ligand at the subfamily level, although FGFR3c is often preferred and quantitative FGFR4 affinity varies by assay (ferguson2021fibroblastgrowthfactor pages 2-3, xie2020fibroblastgrowthfactor pages 3-4) | HSPG or heparin | Mesenchymal–epithelial communication, lung development, and skeletal biology |
| FGF15/FGF19 | Endocrine FGF19 subfamily; FGF15 is the mouse ortholog and FGF19 the human ligand | Principal and particularly selective endocrine ligand for FGFR4. Structural complementarity supports this preference, and hepatic signaling controls bile-acid synthesis (edirisinghe2024decodingfgffgfrsignaling pages 14-15, li2024targetingthefgf19–fgfr4 pages 3-3) | β-Klotho markedly enhances affinity and physiological hepatic signaling; lower-affinity FGFR4 activation can occur without β-Klotho (li2024targetingthefgf19–fgfr4 pages 3-3, edirisinghe2024decodingfgffgfrsignaling pages 14-15) | Enterohepatic FXR–FGF19–FGFR4 feedback, CYP7A1 repression, bile-acid homeostasis, liver regeneration, and FGF19-driven hepatocellular carcinoma |
| FGF16 | FGF9 subfamily; paracrine/canonical | Evidence is conflicting at the subfamily level, but ligand-specific analysis reports that FGF16 does not appreciably interact with FGFR4 and instead favors FGFR2c/FGFR3c; it is not a firmly established physiological FGFR4 ligand (ferguson2021fibroblastgrowthfactor pages 2-3, edirisinghe2024decodingfgffgfrsignaling pages 14-15) | HSPG or heparin for signaling through its established receptors | Cardiac development and tissue-specific mesenchymal signaling |
| FGF17 | FGF8 subfamily; paracrine/canonical | Reported to bind a two-Ig-domain FGFR4 variant; evidence for the full-length physiological receptor is less definitive than for FGF19 or FGF6 (ferguson2021fibroblastgrowthfactor pages 8-9, farooq2021theroleof pages 5-6) | HSPG or heparin | Brain patterning, neuronal development, and organogenesis |
| FGF18 | FGF8 subfamily; paracrine/canonical | Reported at the subfamily level to interact with a two-Ig-domain FGFR4 variant; FGFR3c is generally a prominent receptor (ferguson2021fibroblastgrowthfactor pages 8-9) | HSPG or heparin | Skeletal development, chondrogenesis, cartilage homeostasis, and tissue repair |
| FGF20 | FGF9 subfamily; paracrine/canonical | Reported FGFR4 ligand at the subfamily level, but FGFR4-specific affinity and physiological dependence are not well quantified (ferguson2021fibroblastgrowthfactor pages 2-3, xie2020fibroblastgrowthfactor pages 3-4) | HSPG or heparin | Neural development, dopaminergic-neuron biology, and epithelial–mesenchymal signaling |
| FGF21 | Endocrine FGF19 subfamily | Some specificity summaries include FGFR4 among possible receptors, but physiological FGF21 signaling is dominated by β-Klotho complexes with FGFR1c and, contextually, FGFR2c/3c; FGFR4 is not its principal functional receptor (ferguson2021fibroblastgrowthfactor pages 2-3) | β-Klotho; low intrinsic HSPG affinity | Systemic glucose, lipid, energy, and stress metabolism, mainly in adipose and other metabolic tissues |
| FGF23 | Endocrine FGF19 subfamily | Can form an active FGFR4-containing signaling complex; structural work demonstrated an FGF23–FGFR4–α-Klotho–heparan-sulfate assembly and asymmetric receptor dimerization | α-Klotho plus heparan sulfate | Phosphate and vitamin-D homeostasis; pathological FGFR4 signaling in cardiac and airway contexts |
Table: This table summarizes reported FGF–FGFR4 interactions, required coreceptors, and major biological contexts. It distinguishes well-supported physiological ligands—especially FGF19—from subfamily-level or context-dependent assignments.
FGF ligands recognized by FGFR4 include paracrine/canonical FGFs (FGF1, FGF2, FGF4, FGF5, FGF6, FGF8, FGF9, FGF17, FGF18, FGF20) and endocrine FGFs (FGF15/19, FGF21, FGF23) (ferguson2021fibroblastgrowthfactor pages 2-3, ferguson2021fibroblastgrowthfactor pages 8-9, nguyen2024thecomplexityand pages 2-4, farooq2021theroleof pages 5-6). Paracrine FGFs require heparan sulfate proteoglycans (HSPGs) or heparin as coreceptors to stabilize the ligand–receptor complex, while endocrine FGFs signal through Klotho proteins—FGF19 and FGF21 utilize β-Klotho, and FGF23 requires α-Klotho (ferguson2021fibroblastgrowthfactor pages 2-3, nguyen2024thecomplexityand pages 2-4, edirisinghe2024decodingfgffgfrsignaling pages 14-15).
Upon FGF ligand binding, assisted by appropriate coreceptors, FGFR4 undergoes receptor dimerization and conformational changes that bring the intracellular kinase domains into proximity (he2025fgfraberrationsin pages 2-4, xie2020fibroblastgrowthfactor pages 3-4, xie2020fibroblastgrowthfactor pages 4-5). This enables trans-autophosphorylation on tyrosine residues within the activation loop and other regulatory sites, fully activating the kinase (xie2020fibroblastgrowthfactor pages 3-4, xie2020fibroblastgrowthfactor pages 4-5, edirisinghe2024decodingfgffgfrsignaling pages 3-4). The activated FGFR4 kinase catalyzes ATP-dependent phosphorylation of tyrosine residues on two principal intracellular substrates:
FRS2α (FGFR substrate 2α): A membrane-associated adaptor protein phosphorylated on multiple tyrosine residues (Tyr-196, Tyr-306, Tyr-349, Tyr-392, Tyr-436, Tyr-471), creating docking sites for GRB2, SOS, and GAB1, thereby initiating RAS/MAPK and PI3K/AKT signaling cascades (liu2026fgffamilyin pages 3-4, xie2020fibroblastgrowthfactor pages 3-4, xie2020fibroblastgrowthfactor pages 4-5, edirisinghe2024decodingfgffgfrsignaling pages 3-4).
PLCγ (Phospholipase C gamma): Recruited to phosphorylated FGFR4 docking sites and activated through tyrosine phosphorylation (including Tyr-783), enabling it to hydrolyze PIP2 into IP3 and DAG, thereby controlling calcium mobilization and PKC activation (liu2026fgffamilyin pages 3-4, xie2020fibroblastgrowthfactor pages 3-4, xie2020fibroblastgrowthfactor pages 4-5, edirisinghe2024decodingfgffgfrsignaling pages 3-4).
These phosphorylation events convert FGFR4 activation into a coordinated intracellular signaling response regulating proliferation, survival, differentiation, metabolism, and calcium signaling (liu2026fgffamilyin pages 3-4, xie2020fibroblastgrowthfactor pages 3-4, ferguson2021fibroblastgrowthfactor pages 3-5).
FGFR4 is primarily localized at the plasma membrane, where it functions as a cell-surface receptor capable of binding circulating or locally presented FGF ligands (szybowska2021negativeregulationof pages 6-7, szybowska2021negativeregulationof pages 2-4, szybowska2021negativeregulationof pages 4-6). Immunofluorescence studies have detected FGFR4 both at the plasma membrane and in intracellular vesicular compartments, indicating active receptor trafficking (phillips2022glycosylationoffgfr4 pages 6-8).
Following ligand binding and activation, FGFR4 undergoes clathrin-mediated endocytosis (CME), a distinct mechanism compared to FGFR3, which can utilize both CME and clathrin-independent pathways (szybowska2021negativeregulationof pages 2-4, szybowska2021negativeregulationof pages 4-6). A key distinguishing feature of FGFR4 trafficking is its preferential sorting to recycling compartments rather than lysosomal degradation pathways (szybowska2021negativeregulationof pages 6-7, szybowska2021negativeregulationof pages 2-4, szybowska2021negativeregulationof pages 4-6, ferguson2021fibroblastgrowthfactor pages 5-7). This recycling route, mediated by Rab11, returns FGFR4 to the plasma membrane and is associated with sustained signaling (szybowska2021negativeregulationof pages 6-7, szybowska2021negativeregulationof pages 4-6). In contrast, FGFR1–3 are predominantly directed to late endosomes and lysosomes for degradation after FGF1 stimulation (szybowska2021negativeregulationof pages 6-7, ferguson2021fibroblastgrowthfactor pages 5-7).
Internalized FGF1–FGFR4 complexes may also traffic through or associate with trans-Golgi network structures (szybowska2021negativeregulationof pages 6-7). Importantly, FGFR signaling can continue from endosomal compartments, and the subcellular localization of FGFR4 influences its signaling output—impaired recycling leads to intracellular FGFR4 accumulation, sustained PLCγ signaling, but reduced AKT pathway activation (szybowska2021negativeregulationof pages 4-6). While FGF and FGFR family members can traffic to the nucleus, the extent and functional significance of nuclear FGFR4 localization remain incompletely defined (szybowska2021negativeregulationof pages 6-7, szybowska2021negativeregulationof pages 2-4).
FGFR4 activation initiates four major intracellular signaling cascades that coordinately regulate cellular responses (liu2023fgfrfamiliesbiological pages 9-11, liu2026fgffamilyin pages 3-4, ferguson2021fibroblastgrowthfactor pages 3-5, edirisinghe2024decodingfgffgfrsignaling pages 1-3).
| Signaling pathway | Key mediators | Downstream effectors | Biological outcomes |
|---|---|---|---|
| RAS–RAF–MEK–ERK (MAPK) | Activated FGFR4 phosphorylates FRS2α, which recruits GRB2 and SOS; SOS activates RAS, followed by RAF and MEK | ERK1/2 and nuclear transcription factors such as ELK1, FOS, JUN, and ETS-family proteins | Promotes context-dependent proliferation, differentiation, migration, invasion, regenerative responses, and cell-cycle gene expression; persistent activation contributes to oncogenesis (ferguson2021fibroblastgrowthfactor pages 3-5, edirisinghe2024decodingfgffgfrsignaling pages 1-3, he2025fgfraberrationsin pages 7-9) |
| PI3K–AKT–mTOR | Phosphorylated FRS2α recruits GRB2 and GAB1; GAB1 recruits PI3K, leading to PIP3-dependent activation of AKT | mTORC1, PDK1, TSC2, FOXO proteins, and apoptosis regulators including BAD, BAX, and caspase-9 | Supports cell survival, growth, protein synthesis, metabolism, angiogenesis, and resistance to apoptosis; aberrant FGFR4 signaling can promote tumor progression and metastasis (liu2026fgffamilyin pages 3-4, edirisinghe2024decodingfgffgfrsignaling pages 1-3, he2025fgfraberrationsin pages 7-9) |
| PLCγ–PKC–Ca²⁺ | PLCγ binds a phosphorylated receptor docking site and is phosphorylated; activated PLCγ hydrolyzes PIP2 into IP3 and DAG | IP3-induced intracellular Ca²⁺ release, PKC, NFAT, and calcium-dependent signaling proteins | Controls calcium signaling, transcription, differentiation, migration, and receptor regulation; in FGFR4-driven HCC, PLCγ/ERK-dependent calcium entry can support cancer stem-cell self-renewal (liu2023fgfrfamiliesbiological pages 9-11, liu2026fgffamilyin pages 3-4, ferguson2021fibroblastgrowthfactor pages 3-5) |
| SRC–STAT3 / JAK–STAT | Activated FGFR4 engages SRC and, depending on context, JAK-associated signaling; STAT3 is phosphorylated and incorporated into signaling complexes | STAT3 dimerization and nuclear translocation, followed by transcriptional regulation; STAT1 and STAT5 can also participate in broader FGFR signaling | Regulates survival, proliferation, inflammatory and oncogenic transcription programs. In FGF19-expressing HCC cells, FGFR4, SRC, and STAT3 form an endosomal complex, with SRC required for delivery of the signaling complex and STAT3 to the nucleus (liu2023fgfrfamiliesbiological pages 9-11, ferguson2021fibroblastgrowthfactor pages 3-5) |
Table: The table summarizes the four principal signaling branches activated downstream of FGFR4, from proximal adaptors to functional outputs. These pathways explain how receptor activation regulates proliferation, survival, metabolism, calcium signaling, and transcription.
The RAS/MAPK/ERK pathway is a central regulator of proliferation and differentiation downstream of FGFR4 (liu2026fgffamilyin pages 3-4, ferguson2021fibroblastgrowthfactor pages 3-5, edirisinghe2024decodingfgffgfrsignaling pages 1-3, he2025fgfraberrationsin pages 7-9). Phosphorylated FRS2α recruits GRB2 and SOS, leading to RAS activation, followed by sequential activation of RAF, MEK, and ERK1/2 (ferguson2021fibroblastgrowthfactor pages 3-5, edirisinghe2024decodingfgffgfrsignaling pages 1-3, he2025fgfraberrationsin pages 7-9). Activated ERK1/2 translocates to the nucleus and phosphorylates transcription factors including ELK1, FOS, JUN, and ETS-family members, driving cell-cycle gene expression and proliferative responses (ferguson2021fibroblastgrowthfactor pages 3-5, he2025fgfraberrationsin pages 7-9). Persistent MAPK activation contributes to oncogenic signaling in FGFR4-driven cancers (liu2023fgfrfamiliesbiological pages 9-11, ferguson2021fibroblastgrowthfactor pages 3-5, hu2026fgfrsignalingand pages 3-4).
The PI3K/AKT pathway promotes cell survival, growth, metabolism, and resistance to apoptosis (liu2026fgffamilyin pages 3-4, edirisinghe2024decodingfgffgfrsignaling pages 1-3, he2025fgfraberrationsin pages 7-9). FRS2α-recruited GRB2 and GAB1 activate PI3K, generating PIP3 and activating AKT and PDK1 (ferguson2021fibroblastgrowthfactor pages 3-5, edirisinghe2024decodingfgffgfrsignaling pages 1-3, he2025fgfraberrationsin pages 7-9). AKT phosphorylates numerous substrates, including TSC2, FOXO transcription factors, and apoptosis regulators such as BAD, BAX, and caspase-9, thereby supporting survival and metabolic reprogramming (liu2026fgffamilyin pages 3-4, edirisinghe2024decodingfgffgfrsignaling pages 1-3). Downstream mTORC1 activation regulates protein synthesis and cell growth (liu2026fgffamilyin pages 3-4, he2025fgfraberrationsin pages 7-9). In FGFR4-driven hepatocellular carcinoma, the PI3K/AKT/HIF1α axis can establish positive feedback loops promoting metastasis (liu2023fgfrfamiliesbiological pages 9-11).
PLCγ binds to phosphorylated FGFR4 docking sites and, upon activation, hydrolyzes PIP2 into IP3 and DAG (liu2026fgffamilyin pages 3-4, ferguson2021fibroblastgrowthfactor pages 3-5, edirisinghe2024decodingfgffgfrsignaling pages 1-3, he2025fgfraberrationsin pages 7-9). IP3 triggers intracellular calcium release from the endoplasmic reticulum, while DAG and calcium together activate protein kinase C (PKC) (liu2026fgffamilyin pages 3-4, ferguson2021fibroblastgrowthfactor pages 3-5, he2025fgfraberrationsin pages 7-9, he2025fgfraberrationsin pages 9-10). This pathway regulates calcium-dependent transcription factors like NFAT, influences differentiation and migration, and can support cancer stem-cell self-renewal through store-operated calcium entry in FGFR4-expressing hepatocellular carcinoma (liu2023fgfrfamiliesbiological pages 9-11, ferguson2021fibroblastgrowthfactor pages 3-5).
FGFR4 can activate STAT transcription factors, particularly STAT3, through both direct and SRC-mediated mechanisms (liu2023fgfrfamiliesbiological pages 9-11, ferguson2021fibroblastgrowthfactor pages 3-5, edirisinghe2024decodingfgffgfrsignaling pages 1-3). In FGF19-expressing hepatocellular carcinoma cells, FGFR4 forms an endosomal signaling complex with SRC and STAT3 that traffics to the nucleus, where STAT3 functions as a transcriptional regulator (liu2023fgfrfamiliesbiological pages 9-11). SRC is essential for endosomal delivery of this complex and nuclear STAT3 signaling (liu2023fgfrfamiliesbiological pages 9-11). This pathway regulates survival, proliferation, and oncogenic transcription programs (liu2023fgfrfamiliesbiological pages 9-11, ferguson2021fibroblastgrowthfactor pages 3-5, edirisinghe2024decodingfgffgfrsignaling pages 1-3).
A defining physiological role of FGFR4 is its central function in the enterohepatic regulation of bile acid synthesis through the FGF19–FGFR4–β-Klotho signaling axis (li2024targetingthefgf19–fgfr4 pages 3-3, li2024targetingthefgf19–fgfr4 pages 2-3, li2024targetingthefgf19–fgfr4 pages 2-2, edirisinghe2024decodingfgffgfrsignaling pages 14-15). This endocrine feedback loop operates as follows:
Following a meal, bile acids reach the ileum and activate the nuclear receptor FXR (farnesoid X receptor), which induces transcription and secretion of FGF19 (or FGF15 in mice) (li2024targetingthefgf19–fgfr4 pages 3-3, li2024targetingthefgf19–fgfr4 pages 2-3, li2024targetingthefgf19–fgfr4 pages 2-2, xu2026fgf19insolid pages 6-7). Circulating FGF19 then binds to the hepatic FGFR4–β-Klotho receptor complex on hepatocytes, activating downstream ERK1/2 and JNK signaling (li2024targetingthefgf19–fgfr4 pages 3-3, li2024targetingthefgf19–fgfr4 pages 2-3, li2024targetingthefgf19–fgfr4 pages 2-2). This signal transcriptionally suppresses CYP7A1 (cholesterol 7α-hydroxylase), the rate-limiting enzyme in the classical bile acid synthesis pathway, thereby reducing hepatic conversion of cholesterol into bile acids and maintaining bile acid homeostasis (li2024targetingthefgf19–fgfr4 pages 3-3, li2024targetingthefgf19–fgfr4 pages 2-3, li2024targetingthefgf19–fgfr4 pages 2-2, xu2026fgf19insolid pages 6-7, edirisinghe2024decodingfgffgfrsignaling pages 14-15, li2024targetingthefgf19–fgfr4 pages 16-16).
Experimental evidence strongly supports this model: liver-specific FGFR4 knockdown in mice fed a high-fat diet increased bile acid synthesis, elevated serum and hepatic bile acids, and upregulated Cyp7a1 expression, demonstrating that hepatic FGFR4 normally restrains bile acid production (moreau2023liverspecificfgfr4knockdown pages 5-8). Conversely, FGFR4-deficient mice exhibit elevated cholesterol metabolism and bile acid synthesis (li2024targetingthefgf19–fgfr4 pages 16-16). This pathway is therapeutically relevant for cholestatic diseases such as primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), as well as metabolic disorders including nonalcoholic steatohepatitis (NASH) (li2024targetingthefgf19–fgfr4 pages 3-3, li2024targetingthefgf19–fgfr4 pages 14-14).
FGFR4 plays an essential role in liver regeneration following injury (li2024targetingthefgf19–fgfr4 pages 14-14, ornitz2022newdevelopmentsin pages 59-60). Loss of FGFR4 severely impairs liver regeneration after partial hepatectomy, and combined deletion of FGFR1, FGFR2, and FGFR4 in hepatocytes causes liver failure, demonstrating the critical and partially redundant functions of FGFR signaling in hepatic tissue (ornitz2022newdevelopmentsin pages 59-60). FGF19 signaling through hepatic FGFR4 accelerates restoration of liver mass in wild-type mice but not in FGFR4-knockdown animals (li2024targetingthefgf19–fgfr4 pages 14-14). FGFR4 is predominantly expressed in liver and lung tissues, with particularly important hepatic functions (liu2023fgfrfamiliesbiological pages 9-11, ornitz2022newdevelopmentsin pages 59-60, xu2026fgf19insolid pages 6-7, li2024targetingthefgf19–fgfr4 pages 14-14).
Aberrant FGFR4 signaling, particularly through the FGF19–FGFR4 axis, is a critical oncogenic driver in multiple cancer types, most notably hepatocellular carcinoma (HCC) (li2024targetingthefgf19–fgfr4 pages 12-13, miranda2020developmentofa pages 1-2, li2024targetingthefgf19–fgfr4 pages 11-12, xu2026fgf19insolid pages 31-33, xu2026fgf19insolid pages 30-31). Approximately 30% of HCC patients have tumors with increased FGFR4 expression, and FGF19 amplification occurs in a substantial subset (miranda2020developmentofa pages 1-2). FGF19/FGFR4 pathway activation promotes tumor-cell proliferation, survival, invasion, metastasis, angiogenesis, altered metabolism, and treatment resistance (miranda2020developmentofa pages 1-2, li2024targetingthefgf19–fgfr4 pages 11-12, xu2026fgf19insolid pages 31-33, xu2026fgf19insolid pages 30-31).
In HCC models, FGF19 transgenic mice develop liver tumors, and this tumorigenesis is prevented by FGFR4 knockout, establishing FGFR4 as the critical mediator of FGF19-driven hepatocarcinogenesis (miranda2020developmentofa pages 1-2). Beyond HCC, FGFR4 overexpression has been reported in colorectal, breast, gastric, thyroid, nasopharyngeal, and other cancers, where it contributes to oncogenic signaling, epithelial–mesenchymal transition, metastasis, and resistance to chemotherapy (liu2023fgfrfamiliesbiological pages 9-11, xu2026fgf19insolid pages 30-31, nguyen2024thecomplexityand pages 14-16).
Significant progress has been made in developing highly selective FGFR4 inhibitors that exploit the unique Cys552 residue for covalent targeting (li2024targetingthefgf19–fgfr4 pages 12-13, miranda2020developmentofa pages 1-2, li2024targetingthefgf19–fgfr4 pages 11-12, xu2026fgf19insolid pages 31-33, schwarz2024developmentofhighly pages 52-55). In 2024, a new class of SNAr-based covalent FGFR4 inhibitors was reported, demonstrating low to subnanomolar potency, efficient covalent inactivation kinetics, excellent selectivity against FGFR1–3, good microsomal stability, and nanomolar cellular potency (schwarz2024developmentofhighly pages 52-55).
Several selective FGFR4 inhibitors have advanced into clinical trials for FGF19-positive HCC and intrahepatic cholangiocarcinoma (li2024targetingthefgf19–fgfr4 pages 12-13, li2024targetingthefgf19–fgfr4 pages 11-12, xu2026fgf19insolid pages 31-33, nguyen2024thecomplexityand pages 12-14):
H3B-6527: A highly selective, irreversible FGFR4 inhibitor that received FDA orphan drug designation. In phase I trials in advanced HCC, it produced a 16.7% overall response rate, 10.6-month overall survival, and 4.1-month progression-free survival (li2024targetingthefgf19–fgfr4 pages 12-13).
Roblitinib (FGF401): A reversible-covalent FGFR4 inhibitor evaluated alone and in combination with the PD-1 inhibitor spartalizumab. While responses were observed, activity was modest, potentially because patients were not preselected for FGF19–FGFR4 pathway abnormalities (li2024targetingthefgf19–fgfr4 pages 12-13, li2024targetingthefgf19–fgfr4 pages 11-12).
Fisogatinib (BLU-554): A selective covalent FGFR4 inhibitor evaluated in phase Ib/II trials, including combination with the anti-PD-L1 antibody CS1001 in advanced or metastatic HCC (li2024targetingthefgf19–fgfr4 pages 12-13, li2024targetingthefgf19–fgfr4 pages 11-12, nguyen2024thecomplexityand pages 12-14, schwarz2024developmentofhighly pages 52-55).
Irpagratinib (ABSK011): An irreversible FGFR4 inhibitor targeting Cys552 that, in previously treated advanced HCC patients with FGF19 overexpression, produced a 44.8% objective response rate, 7.4-month median response duration, and 5.5-month median progression-free survival (xu2026fgf19insolid pages 31-33, nguyen2024thecomplexityand pages 12-14).
These clinical data underscore the importance of patient selection based on FGF19 overexpression or FGFR4 positivity for optimal therapeutic benefit (li2024targetingthefgf19–fgfr4 pages 12-13, nguyen2024thecomplexityand pages 12-14).
A 2023 study demonstrated that liver-specific FGFR4 knockdown in mice on a high-fat diet increased bile acid synthesis and improved hepatic steatosis, suggesting that reducing hepatic FGFR4 signaling may have therapeutic potential for nonalcoholic fatty liver disease (NAFLD) (moreau2023liverspecificfgfr4knockdown pages 5-8, moreau2023liverspecificfgfr4knockdown pages 15-15). This finding expands the therapeutic scope of FGFR4 modulation beyond cancer to include metabolic disorders (li2024targetingthefgf19–fgfr4 pages 12-13, fan2025structurebasedidentificationof pages 22-23).
Recent reviews have synthesized emerging evidence that the FGF19–FGFR4 pathway is relevant not only for cancer but also for cholestatic diseases (PBC, PSC), metabolic abnormalities (NASH), and bile acid homeostasis disorders (li2024targetingthefgf19–fgfr4 pages 3-3, li2024targetingthefgf19–fgfr4 pages 12-13, fan2025structurebasedidentificationof pages 22-23). This expanded pathophysiological framework positions FGFR4 as a therapeutic target spanning oncology, hepatology, and metabolism.
Emerging therapeutic strategies include combinations of FGFR4 inhibitors with immune checkpoint inhibitors (anti-PD-1, anti-PD-L1) and CDK4/6 inhibitors (li2024targetingthefgf19–fgfr4 pages 12-13, li2024targetingthefgf19–fgfr4 pages 11-12, xu2026fgf19insolid pages 31-33, schwarz2024developmentofhighly pages 52-55). Preclinical evidence suggests that pan-FGFR inhibitors such as LY2874455 can overcome resistance to selective FGFR4 inhibitors like fisogatinib, highlighting the need for next-generation agents and rational combination approaches (li2024targetingthefgf19–fgfr4 pages 12-13).
FGFR4 is a receptor tyrosine kinase with distinctive structural features, including a unique Cys552 residue exploited for selective therapeutic targeting and a single c-type isoform conferring specific ligand-binding properties. Its primary molecular function is to bind FGF ligands—particularly FGF19—and transduce signals through tyrosine phosphorylation of FRS2α and PLCγ, activating RAS/MAPK, PI3K/AKT, PLCγ/PKC/Ca²⁺, and SRC/STAT3 pathways. FGFR4 is localized at the plasma membrane and undergoes clathrin-mediated endocytosis with preferential recycling that sustains signaling. Its most well-defined physiological role is in the enterohepatic regulation of bile acid synthesis through the FGF19–FGFR4–β-Klotho axis, which suppresses CYP7A1 and maintains bile acid homeostasis. FGFR4 is also critical for liver regeneration and, when dysregulated, drives oncogenic signaling in hepatocellular carcinoma and other cancers. Recent developments (2023–2024) include advanced selective covalent inhibitors in clinical trials, expanded therapeutic applications in metabolic and cholestatic diseases, and evidence that modulating hepatic FGFR4 can improve hepatic steatosis, establishing FGFR4 as a multifaceted target in precision medicine.
References
(nguyen2024thecomplexityand pages 6-8): Anh L. Nguyen, Caroline O. B. Facey, and Bruce M. Boman. The complexity and significance of fibroblast growth factor (fgf) signaling for fgf-targeted cancer therapies. Cancers, 17:82, Dec 2024. URL: https://doi.org/10.3390/cancers17010082, doi:10.3390/cancers17010082. This article has 21 citations.
(he2025fgfraberrationsin pages 2-4): Zi-Jie He, Yi-Zhen Chen, Geng-Lin Li, Jin-Tao Wang, Yuxin Wang, Peng-Jie Tu, Yang-Yun Huang, Li-Lan Zhao, Xiao-Jie Pan, Heng-Rui Liu, and Wen-Shu Chen. Fgfr aberrations in solid tumors: mechanistic insights and clinical translation of targeted therapies. Cancers, 18:89, Dec 2025. URL: https://doi.org/10.3390/cancers18010089, doi:10.3390/cancers18010089. This article has 8 citations.
(chioni2021biologicalsignificanceand pages 2-5): Athina-Myrto Chioni and Richard P. Grose. Biological significance and targeting of the fgfr axis in cancer. Cancers, 13:5681, Nov 2021. URL: https://doi.org/10.3390/cancers13225681, doi:10.3390/cancers13225681. This article has 65 citations.
(ferguson2021fibroblastgrowthfactor pages 2-3): Harriet R. Ferguson, Michael P. Smith, and Chiara Francavilla. Fibroblast growth factor receptors (fgfrs) and noncanonical partners in cancer signaling. Cells, 10:1201, May 2021. URL: https://doi.org/10.3390/cells10051201, doi:10.3390/cells10051201. This article has 150 citations.
(astolfi2020theemergingrole pages 1-3): Annalisa Astolfi, Maria Abbondanza Pantaleo, Valentina Indio, Milena Urbini, and Margherita Nannini. The emerging role of the fgf/fgfr pathway in gastrointestinal stromal tumor. International Journal of Molecular Sciences, 21:3313, May 2020. URL: https://doi.org/10.3390/ijms21093313, doi:10.3390/ijms21093313. This article has 51 citations.
(phillips2022glycosylationoffgfr4 pages 6-8): Andrew J. Phillips, Marissa B. Lobl, Yamnah A. Hafeji, Hannah R. Safranek, Ashley M. Mohr, and Justin L. Mott. Glycosylation of fgfr4 in cholangiocarcinoma regulates receptor processing and cancer signaling. Journal of Cellular Biochemistry, 123:568-580, Jan 2022. URL: https://doi.org/10.1002/jcb.30204, doi:10.1002/jcb.30204. This article has 7 citations and is from a peer-reviewed journal.
(nguyen2024thecomplexityand pages 4-6): Anh L. Nguyen, Caroline O. B. Facey, and Bruce M. Boman. The complexity and significance of fibroblast growth factor (fgf) signaling for fgf-targeted cancer therapies. Cancers, 17:82, Dec 2024. URL: https://doi.org/10.3390/cancers17010082, doi:10.3390/cancers17010082. This article has 21 citations.
(edirisinghe2024decodingfgffgfrsignaling pages 14-15): Oshadi Edirisinghe, Gaëtane Ternier, Zeina Alraawi, and Thallapuranam Krishnaswamy Suresh Kumar. Decoding fgf/fgfr signaling: insights into biological functions and disease relevance. Biomolecules, 14:1622, Dec 2024. URL: https://doi.org/10.3390/biom14121622, doi:10.3390/biom14121622. This article has 67 citations.
(ferguson2021fibroblastgrowthfactor pages 3-5): Harriet R. Ferguson, Michael P. Smith, and Chiara Francavilla. Fibroblast growth factor receptors (fgfrs) and noncanonical partners in cancer signaling. Cells, 10:1201, May 2021. URL: https://doi.org/10.3390/cells10051201, doi:10.3390/cells10051201. This article has 150 citations.
(miranda2020developmentofa pages 1-2): Renata Rezende Miranda, Ying Fu, Xiaojuan Chen, John Perino, Ping Cao, John Carpten, Yongheng Chen, and Chao Zhang. Development of a potent and specific fgfr4 inhibitor for the treatment of hepatocellular carcinoma. Journal of medicinal chemistry, 63:11484-11497, Oct 2020. URL: https://doi.org/10.1021/acs.jmedchem.0c00044, doi:10.1021/acs.jmedchem.0c00044. This article has 47 citations and is from a highest quality peer-reviewed journal.
(xie2020fibroblastgrowthfactor pages 3-4): Yangli Xie, Allen Zinkle, Lin Chen, and Moosa Mohammadi. Fibroblast growth factor signalling in osteoarthritis and cartilage repair. Nature Reviews Rheumatology, pages 1-18, Aug 2020. URL: https://doi.org/10.1038/s41584-020-0469-2, doi:10.1038/s41584-020-0469-2. This article has 212 citations and is from a domain leading peer-reviewed journal.
(xie2020fibroblastgrowthfactor pages 4-5): Yangli Xie, Allen Zinkle, Lin Chen, and Moosa Mohammadi. Fibroblast growth factor signalling in osteoarthritis and cartilage repair. Nature Reviews Rheumatology, pages 1-18, Aug 2020. URL: https://doi.org/10.1038/s41584-020-0469-2, doi:10.1038/s41584-020-0469-2. This article has 212 citations and is from a domain leading peer-reviewed journal.
(szybowska2021negativeregulationof pages 6-7): Patrycja Szybowska, Michal Kostas, Jørgen Wesche, Ellen Margrethe Haugsten, and Antoni Wiedlocha. Negative regulation of fgfr (fibroblast growth factor receptor) signaling. Cells, 10:1342, May 2021. URL: https://doi.org/10.3390/cells10061342, doi:10.3390/cells10061342. This article has 67 citations.
(szybowska2021negativeregulationof pages 4-6): Patrycja Szybowska, Michal Kostas, Jørgen Wesche, Ellen Margrethe Haugsten, and Antoni Wiedlocha. Negative regulation of fgfr (fibroblast growth factor receptor) signaling. Cells, 10:1342, May 2021. URL: https://doi.org/10.3390/cells10061342, doi:10.3390/cells10061342. This article has 67 citations.
(schwarz2024developmentofhighly pages 52-55): Moritz Schwarz, Maksym Kurkunov, Florian Wittlinger, Ramona Rudalska, Guiqun Wang, Martin Peter Schwalm, Alexander Rasch, Benedikt Wagner, Stefan A. Laufer, Stefan Knapp, Daniel Dauch, and Matthias Gehringer. Development of highly potent and selective covalent fgfr4 inhibitors based on snar electrophiles. Journal of medicinal chemistry, 67:6549-6569, Apr 2024. URL: https://doi.org/10.1021/acs.jmedchem.3c02483, doi:10.1021/acs.jmedchem.3c02483. This article has 28 citations and is from a highest quality peer-reviewed journal.
(liu2026fgffamilyin pages 3-4): Xiaoyu Liu, Meiling Jing, Yueyi Yang, Qiaoqiao Jin, B. Feng, Pengfei Zhang, Chenguang Niu, Xuchen Hu, and Zheng-Wei Huang. Fgf family in health and disease. Molecular Biomedicine, Mar 2026. URL: https://doi.org/10.1186/s43556-026-00429-0, doi:10.1186/s43556-026-00429-0. This article has 10 citations and is from a peer-reviewed journal.
(nguyen2024thecomplexityand pages 2-4): Anh L. Nguyen, Caroline O. B. Facey, and Bruce M. Boman. The complexity and significance of fibroblast growth factor (fgf) signaling for fgf-targeted cancer therapies. Cancers, 17:82, Dec 2024. URL: https://doi.org/10.3390/cancers17010082, doi:10.3390/cancers17010082. This article has 21 citations.
(farooq2021theroleof pages 5-6): Mariya Farooq, Abdul Waheed Khan, Moon Suk Kim, and Sangdun Choi. The role of fibroblast growth factor (fgf) signaling in tissue repair and regeneration. Cells, 10:3242, Nov 2021. URL: https://doi.org/10.3390/cells10113242, doi:10.3390/cells10113242. This article has 446 citations.
(ferguson2021fibroblastgrowthfactor pages 8-9): Harriet R. Ferguson, Michael P. Smith, and Chiara Francavilla. Fibroblast growth factor receptors (fgfrs) and noncanonical partners in cancer signaling. Cells, 10:1201, May 2021. URL: https://doi.org/10.3390/cells10051201, doi:10.3390/cells10051201. This article has 150 citations.
(li2024targetingthefgf19–fgfr4 pages 3-3): Xiaokun Li, Weiqin Lu, Alexei Kharitonenkov, and Yongde Luo. Targeting the fgf19–fgfr4 pathway for cholestatic, metabolic, and cancerous diseases. Journal of Internal Medicine, 295:292-312, Jan 2024. URL: https://doi.org/10.1111/joim.13767, doi:10.1111/joim.13767. This article has 66 citations and is from a domain leading peer-reviewed journal.
(edirisinghe2024decodingfgffgfrsignaling pages 3-4): Oshadi Edirisinghe, Gaëtane Ternier, Zeina Alraawi, and Thallapuranam Krishnaswamy Suresh Kumar. Decoding fgf/fgfr signaling: insights into biological functions and disease relevance. Biomolecules, 14:1622, Dec 2024. URL: https://doi.org/10.3390/biom14121622, doi:10.3390/biom14121622. This article has 67 citations.
(szybowska2021negativeregulationof pages 2-4): Patrycja Szybowska, Michal Kostas, Jørgen Wesche, Ellen Margrethe Haugsten, and Antoni Wiedlocha. Negative regulation of fgfr (fibroblast growth factor receptor) signaling. Cells, 10:1342, May 2021. URL: https://doi.org/10.3390/cells10061342, doi:10.3390/cells10061342. This article has 67 citations.
(ferguson2021fibroblastgrowthfactor pages 5-7): Harriet R. Ferguson, Michael P. Smith, and Chiara Francavilla. Fibroblast growth factor receptors (fgfrs) and noncanonical partners in cancer signaling. Cells, 10:1201, May 2021. URL: https://doi.org/10.3390/cells10051201, doi:10.3390/cells10051201. This article has 150 citations.
(liu2023fgfrfamiliesbiological pages 9-11): Qing Liu, Jiyu Huang, Weiwei Yan, Zhen Liu, Shu Liu, and Weiyi Fang. Fgfr families: biological functions and therapeutic interventions in tumors. MedComm, Sep 2023. URL: https://doi.org/10.1002/mco2.367, doi:10.1002/mco2.367. This article has 85 citations.
(edirisinghe2024decodingfgffgfrsignaling pages 1-3): Oshadi Edirisinghe, Gaëtane Ternier, Zeina Alraawi, and Thallapuranam Krishnaswamy Suresh Kumar. Decoding fgf/fgfr signaling: insights into biological functions and disease relevance. Biomolecules, 14:1622, Dec 2024. URL: https://doi.org/10.3390/biom14121622, doi:10.3390/biom14121622. This article has 67 citations.
(he2025fgfraberrationsin pages 7-9): Zi-Jie He, Yi-Zhen Chen, Geng-Lin Li, Jin-Tao Wang, Yuxin Wang, Peng-Jie Tu, Yang-Yun Huang, Li-Lan Zhao, Xiao-Jie Pan, Heng-Rui Liu, and Wen-Shu Chen. Fgfr aberrations in solid tumors: mechanistic insights and clinical translation of targeted therapies. Cancers, 18:89, Dec 2025. URL: https://doi.org/10.3390/cancers18010089, doi:10.3390/cancers18010089. This article has 8 citations.
(hu2026fgfrsignalingand pages 3-4): Yi-Nan Hu, Xin-Miao Zhang, Wen Liu, Yu-Qing Wei, Jing-Li Xue, Xiao-Wen Ma, Yuan Cao, and Pei-Feng Li. Fgfr signaling and apoptotic regulation in cancer: links to immune evasion, therapeutic resistance, and treatment re-engagement. Frontiers in Immunology, Sep 2026. URL: https://doi.org/10.3389/fimmu.2026.1953431, doi:10.3389/fimmu.2026.1953431. This article has 0 citations and is from a peer-reviewed journal.
(he2025fgfraberrationsin pages 9-10): Zi-Jie He, Yi-Zhen Chen, Geng-Lin Li, Jin-Tao Wang, Yuxin Wang, Peng-Jie Tu, Yang-Yun Huang, Li-Lan Zhao, Xiao-Jie Pan, Heng-Rui Liu, and Wen-Shu Chen. Fgfr aberrations in solid tumors: mechanistic insights and clinical translation of targeted therapies. Cancers, 18:89, Dec 2025. URL: https://doi.org/10.3390/cancers18010089, doi:10.3390/cancers18010089. This article has 8 citations.
(li2024targetingthefgf19–fgfr4 pages 2-3): Xiaokun Li, Weiqin Lu, Alexei Kharitonenkov, and Yongde Luo. Targeting the fgf19–fgfr4 pathway for cholestatic, metabolic, and cancerous diseases. Journal of Internal Medicine, 295:292-312, Jan 2024. URL: https://doi.org/10.1111/joim.13767, doi:10.1111/joim.13767. This article has 66 citations and is from a domain leading peer-reviewed journal.
(li2024targetingthefgf19–fgfr4 pages 2-2): Xiaokun Li, Weiqin Lu, Alexei Kharitonenkov, and Yongde Luo. Targeting the fgf19–fgfr4 pathway for cholestatic, metabolic, and cancerous diseases. Journal of Internal Medicine, 295:292-312, Jan 2024. URL: https://doi.org/10.1111/joim.13767, doi:10.1111/joim.13767. This article has 66 citations and is from a domain leading peer-reviewed journal.
(xu2026fgf19insolid pages 6-7): Jiayi Xu, Peng Sun, Wenjing Zhu, Xinlin Liu, and Lei-Na Ma. Fgf19 in solid tumors: molecular mechanisms, metabolic reprogramming, and emerging therapeutic opportunities. Theranostics, 16:345-397, Jan 2026. URL: https://doi.org/10.7150/thno.121601, doi:10.7150/thno.121601. This article has 6 citations and is from a domain leading peer-reviewed journal.
(li2024targetingthefgf19–fgfr4 pages 16-16): Xiaokun Li, Weiqin Lu, Alexei Kharitonenkov, and Yongde Luo. Targeting the fgf19–fgfr4 pathway for cholestatic, metabolic, and cancerous diseases. Journal of Internal Medicine, 295:292-312, Jan 2024. URL: https://doi.org/10.1111/joim.13767, doi:10.1111/joim.13767. This article has 66 citations and is from a domain leading peer-reviewed journal.
(moreau2023liverspecificfgfr4knockdown pages 5-8): Francois Moreau, Bruna Brasil Brunao, Xiang-Yu Liu, Frederic Tremblay, Kevin Fitzgerald, Julian Avila-Pacheco, Clary Clish, Ronald C. Kahn, and Samir Softic. Liver-specific fgfr4 knockdown in mice on an hfd increases bile acid synthesis and improves hepatic steatosis. Journal of Lipid Research, 64:100324, Feb 2023. URL: https://doi.org/10.1016/j.jlr.2022.100324, doi:10.1016/j.jlr.2022.100324. This article has 25 citations and is from a peer-reviewed journal.
(li2024targetingthefgf19–fgfr4 pages 14-14): Xiaokun Li, Weiqin Lu, Alexei Kharitonenkov, and Yongde Luo. Targeting the fgf19–fgfr4 pathway for cholestatic, metabolic, and cancerous diseases. Journal of Internal Medicine, 295:292-312, Jan 2024. URL: https://doi.org/10.1111/joim.13767, doi:10.1111/joim.13767. This article has 66 citations and is from a domain leading peer-reviewed journal.
(ornitz2022newdevelopmentsin pages 59-60): D. Ornitz and N. Itoh. New developments in the biology of fibroblast growth factors. WIREs mechanisms of disease, pages e1549, Feb 2022. URL: https://doi.org/10.1002/wsbm.1549, doi:10.1002/wsbm.1549. This article has 171 citations.
(li2024targetingthefgf19–fgfr4 pages 12-13): Xiaokun Li, Weiqin Lu, Alexei Kharitonenkov, and Yongde Luo. Targeting the fgf19–fgfr4 pathway for cholestatic, metabolic, and cancerous diseases. Journal of Internal Medicine, 295:292-312, Jan 2024. URL: https://doi.org/10.1111/joim.13767, doi:10.1111/joim.13767. This article has 66 citations and is from a domain leading peer-reviewed journal.
(li2024targetingthefgf19–fgfr4 pages 11-12): Xiaokun Li, Weiqin Lu, Alexei Kharitonenkov, and Yongde Luo. Targeting the fgf19–fgfr4 pathway for cholestatic, metabolic, and cancerous diseases. Journal of Internal Medicine, 295:292-312, Jan 2024. URL: https://doi.org/10.1111/joim.13767, doi:10.1111/joim.13767. This article has 66 citations and is from a domain leading peer-reviewed journal.
(xu2026fgf19insolid pages 31-33): Jiayi Xu, Peng Sun, Wenjing Zhu, Xinlin Liu, and Lei-Na Ma. Fgf19 in solid tumors: molecular mechanisms, metabolic reprogramming, and emerging therapeutic opportunities. Theranostics, 16:345-397, Jan 2026. URL: https://doi.org/10.7150/thno.121601, doi:10.7150/thno.121601. This article has 6 citations and is from a domain leading peer-reviewed journal.
(xu2026fgf19insolid pages 30-31): Jiayi Xu, Peng Sun, Wenjing Zhu, Xinlin Liu, and Lei-Na Ma. Fgf19 in solid tumors: molecular mechanisms, metabolic reprogramming, and emerging therapeutic opportunities. Theranostics, 16:345-397, Jan 2026. URL: https://doi.org/10.7150/thno.121601, doi:10.7150/thno.121601. This article has 6 citations and is from a domain leading peer-reviewed journal.
(nguyen2024thecomplexityand pages 14-16): Anh L. Nguyen, Caroline O. B. Facey, and Bruce M. Boman. The complexity and significance of fibroblast growth factor (fgf) signaling for fgf-targeted cancer therapies. Cancers, 17:82, Dec 2024. URL: https://doi.org/10.3390/cancers17010082, doi:10.3390/cancers17010082. This article has 21 citations.
(nguyen2024thecomplexityand pages 12-14): Anh L. Nguyen, Caroline O. B. Facey, and Bruce M. Boman. The complexity and significance of fibroblast growth factor (fgf) signaling for fgf-targeted cancer therapies. Cancers, 17:82, Dec 2024. URL: https://doi.org/10.3390/cancers17010082, doi:10.3390/cancers17010082. This article has 21 citations.
(moreau2023liverspecificfgfr4knockdown pages 15-15): Francois Moreau, Bruna Brasil Brunao, Xiang-Yu Liu, Frederic Tremblay, Kevin Fitzgerald, Julian Avila-Pacheco, Clary Clish, Ronald C. Kahn, and Samir Softic. Liver-specific fgfr4 knockdown in mice on an hfd increases bile acid synthesis and improves hepatic steatosis. Journal of Lipid Research, 64:100324, Feb 2023. URL: https://doi.org/10.1016/j.jlr.2022.100324, doi:10.1016/j.jlr.2022.100324. This article has 25 citations and is from a peer-reviewed journal.
(fan2025structurebasedidentificationof pages 22-23): Lin Fan, Hui Xie, Weiyu Wang, Guizhu Peng, Zhen Fu, and Qifa Ye. Structure-based identification of potent fibroblast growth factor receptor 4 (fgfr4) inhibitors as potential therapeutics for hepatocellular carcinoma. PeerJ, 13:e19183, Jun 2025. URL: https://doi.org/10.7717/peerj.19183, doi:10.7717/peerj.19183. This article has 1 citations and is from a peer-reviewed journal.