It has been previously reported that P16, COX2, MGMT, hMSH2 and hMLH1 gene could be more frequently found in cancer tissues than in remote normal-appearing tissues, and hypermethylation could not be found in normal tissues.13,14,22 The present study has shown that individuals with methylation of MGMT and hMLH1 may influence the susceptibility of gastric cancer, which proved DNA methylation may play a role in the development of gastric cancer. This evidence concerns the gene MSH2 and gastric cancer.