RAD18 and skin squamous cell carcinoma: The AA, AG, and GG genotype frequencies of RAD18 rs615967 were 36.1%, 47.3%, and 16.6% in normal controls; 31.1%, 49.4%, and 19.5% in the CIN III group and 26.6%, 49.7%, and 23.8% in the CSCC group, respectively.