In the present study, we found that the XPD Lys751Gln polymorphism was significantly associated with increased HCC risk in HBV-positive patients but not in HBV-negative subgroup, which was consistent with the studies conducted by Long et al31 and Xu et al.32 The possible mechanism for the preferentially increased HCC risk of XPD Lys751Gln polymorphism in HBV-positive patients is that the DNA repair functions of the XPD have been reduced by the XPD Lys751Gln polymorphism, making them more vulnerable to cancer development. This evidence concerns the gene ERCC2 and hepatocellular carcinoma.