| Evidence category | Key findings | Study type/methods | Quantitative/statistical data (HR/beta/p-values/sample size) | Year | Citation ID |
|---|---|---|---|---|---|
| identity/domains | FBXO39 is the human gene/protein matching UniProt Q8N4B4 and is described in the literature as F-box protein 39, a member of the F-box family; available snippets support SCF E3 ligase adaptor context but do not provide direct experimental confirmation of its LRR domains or family-specific biochemistry. | Database/disease-association aggregation; family-context statements in experimental papers and reviews | Open Targets lists approved symbol FBXO39 linked to ENSG00000177294; no direct domain statistics in retrieved snippets | 2025/NA | (pqac-00000000, pqac-00000001) |
| molecular function | Available direct evidence supports a pro-proliferative, anti-apoptotic role in U-2OS osteosarcoma cells; broader literature frames FBXO39 as an F-box protein involved in substrate recognition for SCF ubiquitin ligases. | Lentiviral shRNA knockdown, RT-qPCR, western blot, Celigo cell counting, MTT, caspase 3/7 assay, Annexin V FACS | Knockdown increased caspase 3/7 activity vs control (P<0.01) and significantly reduced proliferation; statistical threshold reported as P<0.05/P<0.01 | 2018 | (pqac-00000001, pqac-00000008) |
| substrates/mechanism | No experimentally validated substrate is provided in the 2018 osteosarcoma or 2025 GBM snippets. A later mechanistic report (outside the user's 2023–2024 priority window) proposes that FBXO39 promotes colorectal cancer by mediating p53 degradation, increasing LDHA-driven aerobic glycolysis. | Mechanistic cancer study using Co-IP, ubiquitination assay, MG132 treatment, ChIP-qPCR, dual-luciferase assay, Seahorse OCR/ECAR, xenografts | Xenograft design included 1×10^6 CRC cells, n=5 mice; excerpt states FBXO39 was an independent risk factor, but no HR/p-value numbers were provided in the snippet | 2026 | (pqac-00000004) |
| localization | No direct subcellular localization data for FBXO39 were present in the retrieved evidence snippets. | No direct localization assay in retrieved snippets | Not reported | NA | (pqac-00000001, pqac-00000003) |
| expression/CTA | FBXO39 is repeatedly described as a cancer-testis antigen (CTA), originally identified as BCP-20/FBXO39 in colon cancer by SEREX; expression is characterized as testis-restricted among normal tissues and aberrantly expressed in multiple cancers. In CRC, one study found expression restricted to tumor tissues, using testis as positive control. | SEREX discovery; RT-PCR in tumor vs adjacent normal tissue; review/bioinformatic synthesis | CRC cohort n=36; FBXO39 expression detected in all stage-0 tumor samples; no FBXO39-specific p-value given in the excerpt for tumor restriction | 2018–2025 | (pqac-00000002, pqac-00000005, pqac-00000006) |
| disease associations/prognosis | CRC: FBXO39 expression associated with lymph node involvement and proposed prognostic value. GBM: expression reported upregulated in 29 tumors vs 2 normals, but Cox results in TCGA/CGGA were not statistically significant in the provided excerpt. Glioma/GBM reviews also summarize links to poorer prognosis, invasion, migration, growth, and stemness. Open Targets lists disease associations for glioblastoma, cervical carcinoma, cervical squamous cell carcinoma, colorectal carcinoma, and breast cancer. | RT-PCR; TCGA/CGGA bioinformatics; Kaplan-Meier/Cox analyses; review synthesis; Open Targets evidence aggregation | CRC cohort n=36; GBM local cohort 29 tumors vs 2 normals; TCGA Cox: β=-0.354, HR=0.702, 95% CI 0.218–2.263, P=0.554; CGGA Cox: β=0.196, HR=1.217, 95% CI 0.957–1.547, P=0.109; local cohort survival P=0.12 | 2018–2025 | (pqac-00000003, pqac-00000005, pqac-00000007, pqac-00000000) |
| applications/therapeutics | Current translational relevance is mainly as a biomarker/immunotherapy candidate rather than a validated drug target. CTA-focused reviews identify FBXO39 as a potential immunotherapy antigen in digestive cancers and glioma, and a 2025 GBM study concluded FBXO39 expression measurement may have prognostic biomarker utility. No FBXO39-specific clinical trial was identified in the retrieved evidence. | CTA reviews; bioinformatic/clinical biomarker study | Open Targets evidence size = 3 for each listed disease association in retrieved output; GBM validation cohort n=29 | 2023–2025 | (pqac-00000002, pqac-00000007, pqac-00000000) |


*Table: This table consolidates the retrieved evidence for human FBXO39/Q8N4B4 across identity, function, mechanism, expression, prognosis, and translational relevance. It highlights where evidence is direct versus limited, which is useful for cautious functional annotation of this poorly characterized gene.*