For instance, overexpression of the DNA repair mediator, xeroderma pigmentosum complementation group C (XPC) (Sugasawa et al., 1998; Shell et al., 2013), enhances the repairment of damaged DNA via nucleotide excision repair (NER) process in cancer cells, rendering them the capability of escaping from cytotoxicity induced by chemotherapeutic drugs (Fautrel et al., 2005). The gene discussed is XPC; the disease is cancer.