# FOS

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

## TL;DR

FOS (Fos proto-oncogene, AP-1 transcription factor subunit) 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 Colorectal cancer.

## Summary

Nuclear phosphoprotein which forms a tight but non-covalently linked complex with the JUN/AP-1 transcription factor. In the heterodimer, FOS and JUN/AP-1 basic regions each seems to interact with symmetrical DNA half sites. On TGF-beta activation, forms a multimeric SMAD3/SMAD4/JUN/FOS complex at the AP1/SMAD-binding site to regulate TGF-beta-mediated signalling.

CIViC holds 3 clinical evidence items and 1 assertion across 2 variants, naming Irbesartan.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: Fos proto-oncogene, AP-1 transcription factor subunit; c-fos; AP-1
- Tags: cancer-genes-wave
- Symbol: FOS
- Class: other
- Biology: Nuclear phosphoprotein which forms a tight but non-covalently linked complex with the JUN/AP-1 transcription factor. In the heterodimer, FOS and JUN/AP-1 basic regions each seems to interact with symmetrical DNA half sites. On TGF-beta activation, forms a multimeric SMAD3/SMAD4/JUN/FOS complex at the AP1/SMAD-binding site to regulate TGF-beta-mediated signalling. Has a critical function in regulating the development of cells destined to form and maintain the skeleton. It is thought to have an important role in signal transduction, cell proliferation and differentiation. In growing cells, activates phospholipid synthesis, possibly by activating CDS1 and PI4K2A. Location: Nucleus; Endoplasmic reticulum; Cytoplasm, cytosol (UniProt). Locus 14q24.3 (HGNC).
- Where found: Colorectal 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 3 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.
- Diseases the sources name that have no OnCo cancer page yet, so they are not linked: Osteoblastoma.

## Sources

- HGNC HGNC:3796: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:3796
- UniProt P01100: https://www.uniprot.org/uniprotkb/P01100/entry
- NCBI Gene 2353: https://www.ncbi.nlm.nih.gov/gene/2353
- Ensembl ENSG00000170345: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000170345

## Connected records

- collections: [CIViC](https://onco.cc/collections/civic/)
- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/)

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