# CCNH

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

## TL;DR

CCNH (Cyclin-H) is a protein that switches other genes on and off. In the public catalogues the evidence so far is association rather than a proven role.

## Summary

Component of the CDK-activating kinase (CAK) complex, a master regulator of CDK activity by catalysing the activating threonine phosphorylation of CDKs. Binds and activates cyclin-dependent protein kinase CDK7, the catalytic subunit of CAK. CAK activates major mediators of cell cycle control, including CDK1, CDK2, CDK4 and CDK6, and plays a key role in regulating cell cycle progression.

Open Targets scores its association with cancer at 0.53 (direct and indirect evidence; datatypes literature 0.92, genetic association 0.35, somatic mutation 0.74).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: cyclin H; Cyclin-H; p34; p37; CycH
- Tags: cancer-genes-wave
- Symbol: CCNH
- Class: transcription
- Biology: Component of the CDK-activating kinase (CAK) complex, a master regulator of CDK activity by catalysing the activating threonine phosphorylation of CDKs. Binds and activates cyclin-dependent protein kinase CDK7, the catalytic subunit of CAK. CAK activates major mediators of cell cycle control, including CDK1, CDK2, CDK4 and CDK6, and plays a key role in regulating cell cycle progression. CAK complexed to the core-TFIIH basal transcription factor activates RNA polymerase II by serine phosphorylation of the repetitive C-terminal domain (CTD) of its large subunit (POLR2A), allowing its escape from the promoter and elongation of the transcripts. Involved in cell cycle control and in RNA transcription by RNA polymerase II. Its expression and activity are constant throughout the cell cycle. Location: Nucleus (UniProt). Locus 5q14.3 (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:1594: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:1594
- UniProt P51946: https://www.uniprot.org/uniprotkb/P51946/entry
- NCBI Gene 902: https://www.ncbi.nlm.nih.gov/gene/902
- Ensembl ENSG00000134480: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000134480

## Connected records

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

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