KMT2A and acute lymphoblastic leukemia: Certain partner genes are associated with distinct leukemia subtypes, e.g. MLL-AF4 with pro B acute lymphoblastic leukemia (ALL) and MLL-AF9, -AF6 and -AF10 with acute myeloid leukemia (AML) of M4 and M5 subtypes (French–American–British classification) [1].