Chromosome translocations involving mixed lineage leukemia 1 (MLL1, also known as MLL or KMT2A) gene located at chromosome 11q23 cause approximately 75% of acute leukemia in infants and 5–10% in children and adults [1], which can be clinically characterized to be acute lymphocytic leukemia (ALL) or acute myeloid leukemia (AML). The gene discussed is KMT2A; the disease is acute myeloid leukemia.