Although there is controversy regarding the significance of these alterations in the pathogenesis of colon cancer, more and more data indicate that the aberrant methylation of at least some of these genes, such as MLH1 (MutL homolog 1), MGMT (O-6-methylguanine-DNA methytransferase) and HIC1 (hypermethylated in cancer 1) can be pathogenetic in colorectal carcinogenesis [2,6]. Here, MLH1 is linked to medical procedure.