MLH1 and neoplasm: Conversely, abnormal DNA methylation is related to the occurrence of several human diseases (Feinberg et al., 2002; Robertson, 2005), with many studies showing the role of aberrant DNA methylation in the activation of tumor promoter genes (e.g., MAGE, S100P) and silencing of tumor suppressor genes (e.g., VHL, MLH1) in various cancers (Herman and Baylin, 2003; Sato et al., 2004).