ERCC4 and Xeroderma pigmentosum complementation group F: XPF/ERCC4 was originally identified as the defective gene in xeroderma pigmentosum complementation group F (XP-F) [8] since wild type XPF/ERCC4 cDNA complemented human XP-F cells as well as nucleotide-excision repair (NER) deficient Ercc4 and Ercc11 rodent cells [9].