# XPA

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

## TL;DR

XPA (DNA repair protein complementing XP-A cells) is a gene. The public catalogues list it as a DNA repair gene, and the evidence so far is association rather than a proven role. Tied to Skin cancer, Colorectal cancer and Basal cell carcinoma.

## Summary

Involved in DNA nucleotide excision repair (NER). Initiates repair by binding to damaged sites with various affinities, depending on the photoproduct and the transcriptional state of the region. Required for UV-induced CHEK1 phosphorylation and the recruitment of CEP164 to cyclobutane pyrimidine dimmers (CPD), sites of DNA damage after UV irradiation.

Open Targets scores its association with cancer at 0.79 (direct and indirect evidence; datatypes literature 0.94, animal model 0.26, genetic association 0.83, somatic mutation 0.95).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: XPA, DNA damage recognition and repair factor; DNA repair protein complementing XP-A cells; XP1
- Tags: cancer-genes-wave
- Symbol: XPA
- Class: other
- Biology: Involved in DNA nucleotide excision repair (NER). Initiates repair by binding to damaged sites with various affinities, depending on the photoproduct and the transcriptional state of the region. Required for UV-induced CHEK1 phosphorylation and the recruitment of CEP164 to cyclobutane pyrimidine dimmers (CPD), sites of DNA damage after UV irradiation. During NER stimulates the 5'-3' helicase activity of XPD/ERCC2 and the DNA translocase activity of XPB/ERCC3. Connects XPD/ERCC2 and XPB/ERCC3 during NER, retaining DNA near the XPB/ERCC3 active site, and stabilising the complex in a different conformation than in transcribing TFIIH. Location: Nucleus (UniProt). Locus 9q22.33 (HGNC).
- Where found: Skin cancer: Open Targets association 0.62 with skin cancer (MONDO_0002898); Colorectal cancer: Open Targets association 0.51 with colorectal cancer (MONDO_0005575); Basal cell carcinoma: Open Targets association 0.59 with basal cell carcinoma (MONDO_0020804)

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

## Sources

- HGNC HGNC:12814: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:12814
- UniProt P23025: https://www.uniprot.org/uniprotkb/P23025/entry
- NCBI Gene 7507: https://www.ncbi.nlm.nih.gov/gene/7507
- Ensembl ENSG00000136936: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000136936

## Connected records

- collections: [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Basal cell carcinoma](https://onco.cc/cancers/basal-cell-carcinoma/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Skin cancer (all types)](https://onco.cc/cancers/skin-cancer/)

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