{"entity":{"id":"exo1","kind":"target","name":"EXO1","aka":["exonuclease 1","Exonuclease 1","HEX1","hExoI"],"tldr":"EXO1 (Exonuclease 1) is an enzyme. The public catalogues list it as a DNA repair gene, and the evidence so far is association rather than a proven role. Tied to Breast cancer.","summary":"5'->3' double-stranded DNA exonuclease which may also possess a cryptic 3'->5' double-stranded DNA exonuclease activity. Functions in DNA mismatch repair (MMR) to excise mismatch-containing DNA tracts directed by strand breaks located either 5' or 3' to the mismatch. Also exhibits endonuclease activity against 5'-overhanging flap structures similar to those generated by displacement synthesis when DNA polymerase encounters the 5'-end of a downstream Okazaki fragment.\n\nOpen Targets scores its association with cancer at 0.68 (direct and indirect evidence; datatypes literature 0.98, affected pathway 0.87, genetic association 0.74, genetic literature 0.01).","asOf":"2026-09-23","links":[{"label":"HGNC HGNC:3511","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:3511"},{"label":"UniProt Q9UQ84","url":"https://www.uniprot.org/uniprotkb/Q9UQ84/entry"},{"label":"NCBI Gene 9156","url":"https://www.ncbi.nlm.nih.gov/gene/9156"},{"label":"Ensembl ENSG00000174371","url":"https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000174371"}],"tags":["cancer-genes-wave"],"related":["open-targets"],"cancers":["breast-cancer"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":["mismatch-repair-msi"],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"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."],"provenance":{"editedBy":"scripts/fetch-cancer-genes.ts (CIViC, Open Targets, IntOGen, HGNC, UniProt)","editedOn":"2026-09-23"},"symbol":"EXO1","role":["dna-repair"],"evidenceTier":"association-only","sources":[{"label":"HGNC HGNC:3511","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:3511","note":"approved symbol, name, aliases, locus and cross-references (hgnc_complete_set.txt)"},{"label":"UniProt Q9UQ84","url":"https://www.uniprot.org/uniprotkb/Q9UQ84/entry","note":"protein name, function text, keywords and locations (REST API)"},{"label":"Open Targets ENSG00000174371","url":"https://platform.opentargets.org/target/ENSG00000174371/associations","note":"association with cancer (MONDO_0004992) 0.68; per-cancer scores at or above 0.5: breast cancer 0.54 (GraphQL API, CC0)"}],"hgnc":"HGNC:3511","ensembl":"ENSG00000174371","uniprot":"Q9UQ84","entrez":"9156","biology":"5'->3' double-stranded DNA exonuclease which may also possess a cryptic 3'->5' double-stranded DNA exonuclease activity. Functions in DNA mismatch repair (MMR) to excise mismatch-containing DNA tracts directed by strand breaks located either 5' or 3' to the mismatch. Also exhibits endonuclease activity against 5'-overhanging flap structures similar to those generated by displacement synthesis when DNA polymerase encounters the 5'-end of a downstream Okazaki fragment. Required for somatic hypermutation (SHM) and class switch recombination (CSR) of immunoglobulin genes. Essential for male and female meiosis. Location: Nucleus (UniProt). Locus 1q43 (HGNC).","whereFound":["Breast cancer: Open Targets association 0.54 with breast cancer (MONDO_0007254)"],"targetClass":"enzyme","prevalence":[]},"route":"/targets/exo1/","neighbours":{"collection":[{"id":"open-targets","kind":"collection","name":"Open Targets Platform","route":"/collections/open-targets/"}],"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"}],"pathway":[{"id":"mismatch-repair-msi","kind":"pathway","name":"Mismatch repair & microsatellite instability","route":"/pathways/mismatch-repair-msi/"}]}}