Excision Repair Cross Complementing 1 (ERCC1) is a DNA repair enzyme involved in the repair of UV-induced DNA damage. The mammalian ERCC1 polypeptide is required for nucleotide excision repair (NER) of damaged DNA and is homologous to Saccharomyces cerevisiae RAD10, which functions in repair and mitotic intrachromosomal recombination. NER mechanism involves dual incisions on both sides of the damage catalyzed by two nucleases. In mammalian cells XPG cleaves 3' of the DNA lesion while the ERCC1-XPF complex makes the 5'incision. Elevated levels of ERCC1 have also been reported in Cisplatin-resistant cells. ERCC1 overexpression is associated with tumor progression in many malignancies such as ovarian cancer, head squamous cell carcinoma, non-small cell lung cancer (NSCLC), and esophageal cancer.