U2AF1 and acute myeloid leukemia: AML patients with low NEDD4L expression showed relatively higher incidence of FLT3, NPM1, and DNMT3A mutations (P = 0.007, 0.001, and 0.051 respectively) but lower frequency of TP53, TET2, and U2AF1 mutations (P = 0.005, 0.063, and 0.064, respectively) than those with high NEDD4L expression.