Huang et al. examined 772 patients with distal colon cancer and 777 controls and suggested no correlation between all examined XPC polymorphisms (Arg492His, Ala499Val, Lys939Gln) and colorectal cancer risk, however they suggested that the smoking-associated risk in CRC was modified by haplotypes containing the XPC 499Val variant [21]. This evidence concerns the gene XPC and colorectal cancer.