It has been reported that H. pylori infection can lead to genetic and epigenetic changes through activation of intracellular signaling pathways in gastric epithelial cells, such as hypermethylation of MLH1 gene promoter and induction of chronic gastric inflammation, atrophic change, intestinal metaplasia, and cancer,[15–17] which present a strong relationship between H. pylori infection and dMMR/MSI cancer. This evidence concerns the gene MLH1 and cancer.