# PIK3CB

Source: https://onco.cc/targets/pik3cb/  
OnCo record `pik3cb` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

PIK3CB is a protein kinase, an enzyme that switches other proteins on by adding phosphate groups. The public catalogues list it as a drug target, an oncogene driver, a tumour suppressor and a biomarker, and clinical evidence ties its variants to diagnosis, prognosis or drug response.

## Summary

Phosphoinositide-3-kinase (PI3K) phosphorylates phosphatidylinositol derivatives at position 3 of the inositol ring to produce 3-phosphoinositides. Uses ATP and PtdIns(4,5)P2 (phosphatidylinositol 4,5-bisphosphate) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3). PIP3 plays a key role by recruiting PH domain-containing proteins to the membrane, including AKT1 and PDPK1, activating signalling cascades involved in cell growth, survival, proliferation, motility and morphology.

CIViC holds 2 clinical evidence items and 0 assertions across 2 variants, naming Doxorubicin. Open Targets scores its association with cancer at 0.82 (direct and indirect evidence; datatypes clinical 0.67, affected pathway 0.86, literature 0.99, genetic association 0.31, somatic mutation 0.86, animal model 0.39). IntOGen calls it a driver in 5 cohorts (4 activating, 1 loss-of-function), covering Bladder Urothelial Carcinoma, Glioblastoma Multiforme, Prostate Adenocarcinoma.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta; Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit beta isoform; PIK3C1
- Tags: cancer-genes-wave
- Symbol: PIK3CB
- Class: kinase
- Biology: Phosphoinositide-3-kinase (PI3K) phosphorylates phosphatidylinositol derivatives at position 3 of the inositol ring to produce 3-phosphoinositides. Uses ATP and PtdIns(4,5)P2 (phosphatidylinositol 4,5-bisphosphate) to generate phosphatidylinositol 3,4,5-trisphosphate (PIP3). PIP3 plays a key role by recruiting PH domain-containing proteins to the membrane, including AKT1 and PDPK1, activating signalling cascades involved in cell growth, survival, proliferation, motility and morphology. Involved in the activation of AKT1 upon stimulation by G protein-coupled receptor (GPCR) ligands such as CXCL12, sphingosine 1-phosphate, and lysophosphatidic acid. May also act downstream receptor tyrosine kinases. Required in different signalling pathways for stable platelet adhesion and aggregation. Location: Cytoplasm; Nucleus (UniProt). Locus 3q22.3 (HGNC).
- Where found: Breast cancer: Open Targets association 0.67 with breast cancer (MONDO_0007254); Sarcomas: CIViC evidence names this disease; Prostate cancer: IntOGen driver in 2 cohorts (PRAD); Bladder & urothelial cancer: IntOGen driver in 1 cohort (BLCA); Skin cancer: Open Targets association 0.55 with skin cancer (MONDO_0002898); Lung cancer: Open Targets association 0.54 with lung cancer (MONDO_0008903)

## Notes

- Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: Open Targets known-drug datatype score 0.67; IntOGen calls it an activating (Act) driver in 4 cohorts; IntOGen calls it a loss-of-function (LoF) driver in 1 cohort; CIViC holds 2 clinical evidence items on its variants. Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:8976: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:8976
- UniProt P42338: https://www.uniprot.org/uniprotkb/P42338/entry
- NCBI Gene 5291: https://www.ncbi.nlm.nih.gov/gene/5291
- Ensembl ENSG00000051382: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000051382

## Connected records

- collections: [CIViC](https://onco.cc/collections/civic/), [IntOGen](https://onco.cc/collections/intogen/), [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Bladder & urothelial cancer](https://onco.cc/cancers/urothelial/), [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/), [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Ovarian cancer](https://onco.cc/cancers/ovarian/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Sarcomas (soft tissue, bone, GIST)](https://onco.cc/cancers/sarcoma/), [Skin cancer (all types)](https://onco.cc/cancers/skin-cancer/)

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JSON: https://onco.cc/api/v1/entities/pik3cb.json