In a study of 194 patients with secondary and therapy-related AML, Lindsley et al.9 showed that the presence of mutations in SRSF2, SF3B1, U2AF1, ZRSR2, ASXL1, EZH2, BCOR or STAG2 were >95% specific for the diagnosis of sAML, and only NPM1 mutations were specific for pAML. Here, U2AF1 is linked to acute myeloid leukemia.