KMT2A and acute lymphoblastic leukemia: Acute lymphocytic leukemia (ALL) and myeloid leukemia (AML) caused by chromosome translocations of mixed lineage leukemia 1 (MLL1, also known as MLL or KMT2A) account for ~ 70% of the diseases in infants and 5–10% in children and adults with a poor prognosis [1–3].