MLH1 and gastric cancer: At the molecular level, recent studies have found that changes in the genetic and epigenetic characteristics of the GC genome often occur in the early stages of the tumor [37, 38], which supports that hMLH1 promoter methylation-induced MSI-H is more likely to be seen in the early stage (TNM stages I–II) presumed in GC patients, thus defining MSI as an early molecular event of GC.