In summary, we reported the frequent loss of Ndrg2 expression in gastric cancer caused by promoter CpG sites hypermethylation, the significance of the relationship between Ndrg2 expression loss and tumor progression in gastric cancer patients, and the induction of Ndrg2 methylation by H. pylori infection via the activation of NFκB pathway and up-regulation of DNMT3b. The gene discussed is DNMT3B; the disease is gastric cancer.