Targeted mutational analysis of patients with de novo and secondary AML revealed that mutations in SRSF2, SF3B1, U2AF1, ZRSR2, ASXL1, EZH2, BCOR, or STAG2 were highly specific for secondary AML and occurred early in leukemogenesis [101]. This evidence concerns the gene STAG2 and acute myeloid leukemia.