ERCC2-Lys751Gln, hOGG1-Ser326Cys, and the XRCC1-Arg194Trp polymorphisms have been shown to have functional significance and may be in part responsible for the interindividual difference in capacity of DNA repair in the general population and for low DNA repair efficacy in patients with various cancers [25–28]. The gene discussed is XRCC1; the disease is cancer.