MLH1 and gastric cancer: Gastric cancer studies have shown that more than 100 genes exhibit aberrant DNA methylation, including significant changes in methylation of a number of genes commonly implicated in tumorigenesis, such as MLH1, p16, CHFR, and RUNX3 [16, 25-27, 30], and DNA methylation of these genes might be useful for gastric cancer screening, prognostication, and treatment prediction.