# MAFB

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

## TL;DR

MAFB (Transcription factor MafB) 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. Tied to Colorectal cancer.

## Summary

Acts as a transcriptional activator or repressor. Plays a pivotal role in regulating lineage-specific haematopoiesis by repressing ETS1-mediated transcription of erythroid-specific genes in myeloid cells. Required for monocytic, macrophage, osteoclast, podocyte and islet beta cell differentiation.

Open Targets scores its association with cancer at 0.62 (direct and indirect evidence; datatypes literature 0.89, animal model 0.26, genetic association 0.27, somatic mutation 0.93).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: MAF bZIP transcription factor B; Transcription factor MafB
- Tags: cancer-genes-wave
- Symbol: MAFB
- Class: transcription
- Biology: Acts as a transcriptional activator or repressor. Plays a pivotal role in regulating lineage-specific haematopoiesis by repressing ETS1-mediated transcription of erythroid-specific genes in myeloid cells. Required for monocytic, macrophage, osteoclast, podocyte and islet beta cell differentiation. Involved in renal tubule survival and F4/80 maturation. Activates the insulin and glucagon promoters. Together with PAX6, transactivates weakly the glucagon gene promoter through the G1 element. Location: Nucleus (UniProt). Locus 20q12 (HGNC).
- Where found: Colorectal cancer: Open Targets association 0.50 with colorectal cancer (MONDO_0005575)

## 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:6408: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:6408
- UniProt Q9Y5Q3: https://www.uniprot.org/uniprotkb/Q9Y5Q3/entry
- NCBI Gene 9935: https://www.ncbi.nlm.nih.gov/gene/9935
- Ensembl ENSG00000204103: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000204103

## Connected records

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

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