MLH1 and cancer: The modification of DNA methylation within cancer cells is often characterized by hypomethylation of CpG sites and hypermethylation of specific CpG islands, leading to the silencing of tumor suppressor genes such as p16 and hMLH1 (as part of DNA mismatch repair mechanisms) (44, 45), which may be related to differences in TERT methylation status in different cell lines.