Mutations of the XRCC1 gene might increase cancer risk through impairment of XRCC1 interaction with further enzymatic proteins and so induce alterations in DNA repair activity [36,37], and this may subsequently induce carcinogenesis, including tumors of head and neck, lung, breast, esophagus, and multiple other tumors [38,39]. The gene discussed is XRCC1; the disease is cancer.