DOT1L and cancer: Due to the large number of these proteins, only those highly relevant to cancer are described, with a particular focus on histone H3 lysine 79 (H3K79) methyltransferase DOT1L, H3K4 targeting mixed lineage leukemia (MLL) and lysine-specific demethylase 1 (LSD1), and H3K27 methyltransferase EZH2.