# FCGR3A

Source: https://onco.cc/targets/fcgr3a/  
OnCo record `fcgr3a` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

FCGR3A (Low affinity immunoglobulin gamma Fc region receptor III-A) is a gene. The public catalogues list it as a drug target and a biomarker, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Breast cancer and HER2-positive breast cancer.

## Summary

Receptor for the invariable Fc fragment of immunoglobulin gamma (IgG). Optimally activated upon binding of clustered antigen-IgG complexes displayed on cell surfaces, triggers lysis of antibody-coated cells, a process known as antibody-dependent cellular cytotoxicity (ADCC). Does not bind free monomeric IgG, thus avoiding inappropriate effector cell activation in the absence of antigenic trigger.

CIViC holds 2 clinical evidence items and 0 assertions across 1 variant, naming Trastuzumab.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: Fc gamma receptor IIIa; Low affinity immunoglobulin gamma Fc region receptor III-A; CD16; CD16a; FcgammaRIIIa; FcGRIIIA; FCGR3; FCG3
- Tags: cancer-genes-wave
- Symbol: FCGR3A
- Class: other
- Biology: Receptor for the invariable Fc fragment of immunoglobulin gamma (IgG). Optimally activated upon binding of clustered antigen-IgG complexes displayed on cell surfaces, triggers lysis of antibody-coated cells, a process known as antibody-dependent cellular cytotoxicity (ADCC). Does not bind free monomeric IgG, thus avoiding inappropriate effector cell activation in the absence of antigenic trigger. Mediates IgG effector functions on natural killer (NK) cells. Binds antigen-IgG complexes generated upon infection and triggers NK cell-dependent cytokine production and degranulation to limit viral load and propagation. Involved in the generation of memory-like adaptive NK cells capable to produce high amounts of IFNG and to efficiently eliminate virus-infected cells via ADCC. Location: Cell membrane; Secreted (UniProt). Locus 1q23.3 (HGNC).
- Where found: Breast cancer: CIViC evidence names this disease; HER2-positive breast cancer: CIViC evidence names this disease

## 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: CIViC lists 1 therapies; 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:3619: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:3619
- UniProt P08637: https://www.uniprot.org/uniprotkb/P08637/entry
- NCBI Gene 2214: https://www.ncbi.nlm.nih.gov/gene/2214
- Ensembl ENSG00000203747: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000203747

## Connected records

- collections: [CIViC](https://onco.cc/collections/civic/)
- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/)
- pathways: [Complement in cancer](https://onco.cc/pathways/complement-in-cancer/), [NK-cell recognition: missing self & stress ligands](https://onco.cc/pathways/nk-cell-recognition/)

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JSON: https://onco.cc/api/v1/entities/fcgr3a.json