For the purpose of providing a comprehensive and consistent conclusion, a meta-analysis of 90 independent case–control studies was carried out and how SNP rs10505477, rs7837328, rs7014346, and rs6983267 located on CASC8 in the 8q24 region and SNP rs4939827, rs4464148, rs12953717 in the SMAD7 region affect CRC tumorigenesis was investigated. The gene discussed is SMAD7; the disease is colorectal carcinoma.