DNMT1 and colorectal cancer: The KCNQ1 cluster (11p15) contains approximately 10 paternally imprinted genes, whose expression is regulated by a tumor suppressor Kcnq1ot1 [37], also known as LIT1. Loss of expression of Kcnq1ot1 in colorectal cancer [46] and repression in skin cancer [47] is mainly controlled by epigenetic modifications, i.e., aberrant DNA methylation, interaction with DNA (cytosine-5-)-methyltransferase 1 (DNMT1), enrichment of H3 lysine 9 dimethylation (H3K9me2) and reduction of H3 lysine 4 (H3K4) demethylation [46,47,48].