Alterations of the KMT2A gene (also known as mixed lineage leukemia 1, MLL1 or MLL gene) located at 11q23.3 are found in both acute lymphoblastic leukemia (ALL) and AML, making up ∼10% of all leukemia cases in all age groups (Winters and Bernt, 2017). The gene discussed is KMT2A; the disease is acute lymphoblastic leukemia.