# CSK

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

## TL;DR

CSK (Tyrosine-protein kinase CSK) is a protein kinase, an enzyme that switches other proteins on by adding phosphate groups. In the public catalogues the evidence so far is association rather than a proven role.

## Summary

Non-receptor tyrosine-protein kinase that plays an important role in the regulation of cell growth, differentiation, migration and immune response. Phosphorylates tyrosine residues located in the C-terminal tails of Src-family kinases (SFKs) including LCK, SRC, HCK, FYN, LYN, CSK or YES1. Upon tail phosphorylation, Src-family members engage in intramolecular interactions between the phosphotyrosine tail and the SH2 domain that result in an inactive conformation.

Open Targets scores its association with cancer at 0.63 (direct and indirect evidence; datatypes literature 0.94, affected pathway 0.97, animal model 0.33, genetic association 0.15).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: C-terminal Src kinase; Tyrosine-protein kinase CSK
- Tags: cancer-genes-wave
- Symbol: CSK
- Class: kinase
- Biology: Non-receptor tyrosine-protein kinase that plays an important role in the regulation of cell growth, differentiation, migration and immune response. Phosphorylates tyrosine residues located in the C-terminal tails of Src-family kinases (SFKs) including LCK, SRC, HCK, FYN, LYN, CSK or YES1. Upon tail phosphorylation, Src-family members engage in intramolecular interactions between the phosphotyrosine tail and the SH2 domain that result in an inactive conformation. To inhibit SFKs, CSK is recruited to the plasma membrane via binding to transmembrane proteins or adapter proteins located near the plasma membrane. Suppresses signalling by various surface receptors, including T-cell receptor (TCR) and B-cell receptor (BCR) by phosphorylating and maintaining inactive several positive effectors such as FYN or LCK. May act as a negative regulator of EGFR and STAT3 signalling pathways. Location: Cytoplasm; Cell membrane (UniProt). Locus 15q24.1 (HGNC).

## 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: none stated by the sources. Evidence tier "association-only" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:2444: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:2444
- UniProt P41240: https://www.uniprot.org/uniprotkb/P41240/entry
- NCBI Gene 1445: https://www.ncbi.nlm.nih.gov/gene/1445
- Ensembl ENSG00000103653: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000103653

## Connected records

- collections: [Open Targets Platform](https://onco.cc/collections/open-targets/)

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