Two patients had de novo acute myeloid leukemia (AML) one of which had 11q23/MLL-rearranged AML, another patient developed a secondary AML eight months following completion of chemotherapy for osteogenic sarcoma and also was t(9,11),11q23 positive (12) and one had acute undifferentiated leukemia. The gene discussed is KMT2A; the disease is acute myeloid leukemia.