DOT1L and acute lymphoblastic leukemia: In acute lymphoblastic leukemia, rearrangements of the histone lysine N-methyltransferase 2A (KMT2A) gene result in the production of aberrant fusion proteins that recruit DOT1-like histone lysine methyltransferase (DOT1L) to incorrect sites and methylates H3K79, causing the expression of oncogenes such as HOXA9 and MEIS1 [263].