DNMT1 and cancer: A genome-wide RNA interference (RNAi) screen in KRAS-transformed NIH3T3 cells identified 28 genes driving KRAS-mediated epigenetic silencing of FAS; many of them are well-known cancer-associated epigenetic regulators, such as DOT1-like histone H3K79 methyltransferase (DOT1L), enhancer of zeste 2 polycomb repressive complex 2 subunit (Ezh2), sirtuin 6 (Sirt6), DNA methyltransferase 1 (DNMT1), and nucleophosmin 2 (NPM2).