# RAD51B

Source: https://onco.cc/targets/rad51b/  
OnCo record `rad51b` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

RAD51B (DNA repair protein RAD51 homolog 2) is a gene. The public catalogues list it as a drug target, a biomarker, a fusion partner and a DNA repair gene, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Breast cancer, Prostate cancer, Ovarian cancer and 2 more.

## Summary

Involved in the homologous recombination repair (HRR) pathway of double-stranded DNA breaks arising during DNA replication or induced by DNA-damaging agents. May promote the assembly of presynaptic RAD51 nucleoprotein filaments. Binds single-stranded DNA and double-stranded DNA and has DNA-dependent ATPase activity.

CIViC holds 2 clinical evidence items and 0 assertions across 2 variants, naming Olaparib. Open Targets scores its association with cancer at 0.80 (direct and indirect evidence; datatypes literature 0.89, affected pathway 0.87, genetic association 0.64, somatic mutation 0.98).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: RAD51 paralog B; DNA repair protein RAD51 homolog 2; REC2; hREC2; R51H2; RAD51L1
- Tags: cancer-genes-wave
- Symbol: RAD51B
- Class: other
- Biology: Involved in the homologous recombination repair (HRR) pathway of double-stranded DNA breaks arising during DNA replication or induced by DNA-damaging agents. May promote the assembly of presynaptic RAD51 nucleoprotein filaments. Binds single-stranded DNA and double-stranded DNA and has DNA-dependent ATPase activity. Part of the RAD51 paralog protein complex BCDX2 which acts in the BRCA1-BRCA2-dependent HR pathway. Upon DNA damage, BCDX2 acts downstream of BRCA2 recruitment and upstream of RAD51 recruitment. BCDX2 binds predominantly to the intersection of the four duplex arms of the Holliday junction and to junction of replication forks. Location: Nucleus (UniProt). Locus 14q24.1 (HGNC).
- Where found: Breast cancer: Open Targets association 0.68 with breast cancer (MONDO_0007254); Prostate cancer: Open Targets association 0.52 with prostate cancer (MONDO_0008315); CIViC evidence names this disease; Ovarian cancer: Open Targets association 0.56 with ovarian cancer (MONDO_0008170); CIViC evidence names this disease; Lung cancer: Open Targets association 0.54 with lung cancer (MONDO_0008903); Skin cancer: Open Targets association 0.52 with skin cancer (MONDO_0002898)

## 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 2 clinical evidence items on its variants; UniProt disease notes describe a translocation or gene fusion involving the gene; UniProt keyword "DNA repair". Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:9822: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:9822
- UniProt O15315: https://www.uniprot.org/uniprotkb/O15315/entry
- NCBI Gene 5890: https://www.ncbi.nlm.nih.gov/gene/5890
- Ensembl ENSG00000182185: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000182185

## Connected records

- collections: [CIViC](https://onco.cc/collections/civic/), [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Lung cancer (all types)](https://onco.cc/cancers/lung-cancer/), [Ovarian cancer](https://onco.cc/cancers/ovarian/), [Prostate cancer](https://onco.cc/cancers/prostate/), [Skin cancer (all types)](https://onco.cc/cancers/skin-cancer/)

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JSON: https://onco.cc/api/v1/entities/rad51b.json