Synonyms:COFS3, ERCC5, ERCM2, UVDR, XPG, XPGC Background:The human genes correcting DNA repair defects are termed excision-repair cross-complementing or ERCC genes. The ERCC5 gene corrects the excision repair deficiency of Chinese hamster ovary cell line UV135 of complementation group 5. The human ERCC5 gene product is a structure-specific endonuclease required for making the 3-prime incision during DNA nucleotide excision-repair(NER). It also plays an important role in regulating DNA excision repair, removal of bulky lesions caused by environmental chemicals or UV light [PMID:22815677].