{"entity":{"id":"dclre1b","kind":"target","name":"DCLRE1B","aka":["DNA cross-link repair 1B","5' exonuclease Apollo","SNM1B","FLJ12810","FLJ13998","APOLLO"],"tldr":"DCLRE1B (5' exonuclease Apollo) 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.","summary":"5'-3' exonuclease that plays a central role in telomere maintenance and protection during S-phase. Participates in the protection of telomeres against non-homologous end-joining (NHEJ)-mediated repair, thereby ensuring that telomeres do not fuse. Plays a key role in telomeric loop (T loop) formation by being recruited by TERF2 at the leading end telomeres and by processing leading-end telomeres immediately after their replication via its exonuclease activity: generates 3' single-stranded overhang at the leading end telomeres avoiding blunt leading-end telomeres that are vulnerable to end-joining reactions and expose the telomere end in a manner that activates the DNA repair pathways.\n\nOpen Targets scores its association with cancer at 0.55 (direct and indirect evidence; datatypes literature 0.83, genetic association 0.70).","asOf":"2026-09-23","links":[{"label":"HGNC HGNC:17641","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:17641"},{"label":"UniProt Q9H816","url":"https://www.uniprot.org/uniprotkb/Q9H816/entry"},{"label":"NCBI Gene 64858","url":"https://www.ncbi.nlm.nih.gov/gene/64858"},{"label":"Ensembl ENSG00000118655","url":"https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000118655"}],"tags":["cancer-genes-wave"],"related":["open-targets"],"cancers":[],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"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":"DCLRE1B","role":["dna-repair"],"evidenceTier":"association-only","sources":[{"label":"HGNC HGNC:17641","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:17641","note":"approved symbol, name, aliases, locus and cross-references (hgnc_complete_set.txt)"},{"label":"UniProt Q9H816","url":"https://www.uniprot.org/uniprotkb/Q9H816/entry","note":"protein name, function text, keywords and locations (REST API)"},{"label":"Open Targets ENSG00000118655","url":"https://platform.opentargets.org/target/ENSG00000118655/associations","note":"association with cancer (MONDO_0004992) 0.55;  (GraphQL API, CC0)"}],"hgnc":"HGNC:17641","ensembl":"ENSG00000118655","uniprot":"Q9H816","entrez":"64858","biology":"5'-3' exonuclease that plays a central role in telomere maintenance and protection during S-phase. Participates in the protection of telomeres against non-homologous end-joining (NHEJ)-mediated repair, thereby ensuring that telomeres do not fuse. Plays a key role in telomeric loop (T loop) formation by being recruited by TERF2 at the leading end telomeres and by processing leading-end telomeres immediately after their replication via its exonuclease activity: generates 3' single-stranded overhang at the leading end telomeres avoiding blunt leading-end telomeres that are vulnerable to end-joining reactions and expose the telomere end in a manner that activates the DNA repair pathways. Together with TERF2, required to protect telomeres from replicative damage during replication by controlling the amount of DNA topoisomerase (TOP1, TOP2A and TOP2B) needed for telomere replication during fork passage and prevent aberrant telomere topology. Also involved in response to DNA damage: plays a role in response to DNA interstrand cross-links (ICLs) by facilitating double-strand break formation. In case of spindle stress, involved in prophase checkpoint. Location: Chromosome, telomere; Nucleus; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome (UniProt). Locus 1p13.2 (HGNC).","whereFound":[],"targetClass":"enzyme","prevalence":[]},"route":"/targets/dclre1b/","neighbours":{"collection":[{"id":"open-targets","kind":"collection","name":"Open Targets Platform","route":"/collections/open-targets/"}]}}