MGMT and gastritis: For example, Alvarez et al. demonstrated MGMT hypermethylation in chronic, but not in early stages of Helicobacter pylori-associated gastritis [29], and the study of N. Zekri et al. highlighted that long-standing chronic Hepatits C infection with progression to hepatocellular carcinoma is accompanied by promoter methylation of APC gene in early, and that of MGMT in later disease stages [30].