MLH1 and colonic neoplasm: Likewise, epigenetic events (hypermethylation) in the genes hMLH1, p16INK4A and GSTPI can also lead indirectly to tumour progression by promoting genetic instability in several tumour entities, such as breast, prostate, gastric or colon cancer (Baylin and Herman, 2000; Herman and Baylin, 2003).