U2AF1 and acute myeloid leukemia: The IPSS-R total score strongly correlated with OS, PFS, and AML transformation, while the mutation status of U2AF1 (HR = 4.840; 95 % CI, 1.655–14.157; P = 0.004) and SRSF2 (HR = 4.379; 95 % CI, 1.604–11.952; P = 0.004) remained an independent predictor for PFS.