# DNMT3B

Source: https://onco.cc/targets/dnmt3b/  
OnCo record `dnmt3b` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

DNMT3B (DNA (cytosine-5)-methyltransferase 3B) 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

Required for genome-wide de novo methylation and is essential for the establishment of DNA methylation patterns during development. DNA methylation is coordinated with methylation of histones. May preferentially methylates nucleosomal DNA within the nucleosome core region.

Open Targets scores its association with cancer at 0.58 (direct and indirect evidence; datatypes literature 0.99, affected pathway 0.76, genetic association 0.54).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: DNA methyltransferase 3 beta; DNA (cytosine-5)-methyltransferase 3B
- Tags: cancer-genes-wave
- Symbol: DNMT3B
- Class: transcription
- Biology: Required for genome-wide de novo methylation and is essential for the establishment of DNA methylation patterns during development. DNA methylation is coordinated with methylation of histones. May preferentially methylates nucleosomal DNA within the nucleosome core region. May function as transcriptional co-repressor by associating with CBX4 and independently of DNA methylation. Seems to be involved in gene silencing. In association with DNMT1 and via the recruitment of CTCFL/BORIS, involved in activation of BAG1 gene expression by modulating dimethylation of promoter histone H3 at H3K4 and H3K9. Location: Nucleus (UniProt). Locus 20q11.21 (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:2979: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:2979
- UniProt Q9UBC3: https://www.uniprot.org/uniprotkb/Q9UBC3/entry
- NCBI Gene 1789: https://www.ncbi.nlm.nih.gov/gene/1789
- Ensembl ENSG00000088305: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000088305

## Connected records

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

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JSON: https://onco.cc/api/v1/entities/dnmt3b.json