# PIK3R3

Source: https://onco.cc/targets/pik3r3/  
OnCo record `pik3r3` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

PIK3R3 (Phosphatidylinositol 3-kinase regulatory subunit gamma) is a gene. The public catalogues list it as a drug target, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Breast cancer.

## Summary

Binds to activated (phosphorylated) protein-tyrosine kinases through its SH2 domain and regulates their kinase activity. During insulin stimulation, it also binds to IRS-1.

Open Targets scores its association with cancer at 0.63 (direct and indirect evidence; datatypes clinical 0.67, affected pathway 0.76, literature 0.97, genetic association 0.49, somatic mutation 0.50).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: phosphoinositide-3-kinase regulatory subunit 3; Phosphatidylinositol 3-kinase regulatory subunit gamma; p55
- Tags: cancer-genes-wave
- Symbol: PIK3R3
- Class: other
- Biology: Binds to activated (phosphorylated) protein-tyrosine kinases through its SH2 domain and regulates their kinase activity. During insulin stimulation, it also binds to IRS-1. Locus 1p34.1 (HGNC).
- Where found: Breast cancer: Open Targets association 0.51 with breast cancer (MONDO_0007254)

## 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. Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:8981: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:8981
- UniProt Q92569: https://www.uniprot.org/uniprotkb/Q92569/entry
- NCBI Gene 8503: https://www.ncbi.nlm.nih.gov/gene/8503
- Ensembl ENSG00000117461: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000117461

## Connected records

- collections: [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/)

---
JSON: https://onco.cc/api/v1/entities/pik3r3.json