KMT2A and acute myeloid leukemia: Tet1 is a Fe(II)- and alpha-ketoglutarate (α-KG)-dependent DNA hydroxylase that was first discovered as a fusion partner of the mixed lineage leukemia (MLL) gene in a rare form of acute myeloid leukemia (AML) containing the t(10; 11)(q22;q23) translocation [16, 17].