U2AF1 and acute myeloid leukemia: For instance, the mutations of ASXL1, BCOR, EZH2, SF3B1, SRSF2, STAG2, U2AF1, and ZRSR2 genes are added as the defining cytogenetic abnormalities, and patients carrying one of which are considered a member of the AML-MR subgroup, while the subgroup defined by RUNX1 mutation is abolished.