Only two published studies have taken a systematic approach to testing single nucleotide polymorphisms (SNPs) that tag most of the common genetic variation in VDR. Using a tagSNP approach, Poynter [42] and Egan [43] and their colleagues did not find significant associations between VDR SNPs and CRC or colonic adenoma, respectively, in individuals of European descent. The gene discussed is VDR; the disease is colon adenoma.