Specifically, MLL fusion is associated with > 70% of infantile acute lymphoblastic leukemia (ALL), 35 – 50% of infant acute myeloid leukemia (AML), and 1-15% of therapy-related leukemia (e.g. patients treated with topoisomerase II inhibitors) (177). The gene discussed is KMT2A; the disease is acute lymphoblastic leukemia.