XRCC1 and cancer: The observed protective effect of the codon 399Gln allele in our study was also found in several previous studies on association between cancer and XRCC1 genotype. XRCC1 genotype has been reported to be a protective genetic biomarker among bladder cancer (Stern et al., 2001), pancreatic adenocarcinoma (Duell et al., 2002), and gastric cancer patients (Ratnasinghe et al., 2004).