“…XRCC1 gene is regarded an important proteins in the multistep BER pathway, and it is the first mammalian gene isolated that affects cellular sensitivity to ionizing radiation (Thompson et al, 1990). Mutations of XRCC1 may increase the risk of cancers by impairing the interaction of XRCC1 with other enzymatic proteins and consequently altering DNA repair activity (Basso et al, 2007;Tudek, 2007), and subsequently induce the carcinogenesis of head and neck and cancer of lung, esophagus, breast and many other malignancies (Yu et al, 2003;Han et al, 2004). As we known, HBV and HCV may promote chromosomal instability or insertional mutations, and thus to induce the carcinoma development risk.…”