(A) NER involves at least four steps: (a) damage recognition by a complex of bound proteins including XPC, (b) unwinding of the DNA by the TFIIH complex that includes XPD, (c) removal of the damaged single-stranded fragment by molecules including an ERCC1/XPF complex and (d) synthesis by DNA polymerases. (B) The XPF gene map labeled with rs2276466, and four polymorphisms that have been commonly studied for their associations with cancer risk. (C) The XPF protein consists of 916 amino acids, containing an ERCC4 domain. Abbreviations: KEGG, Kyoto Encyclopedia of Genes and Genomes; NER, nucleotide excision repaired.