For instance, MSI, one of the hallmarks of molecular subtypes of colon cancer (Dienstmann et al., 2017), is the consequence of a deficiency in the DNA mismatch repair (MMR) system, which is not only due to the genetic mutation of MMR-related genes, but also the results of hypermethylation of MLH1 gene (Herman et al., 1998). Here, MLH1 is linked to colonic neoplasm.