U2AF1 and myelodysplastic syndrome: In myelodysplastic syndrome (MDS) patients, gene sequencing studies of patients’ samples2–11 have revealed that genes encoding RNA splicing factors, SF3B1, U2AF1, SRSF2, ZRSR2, and LUC7L2,2,12–14 had a significantly higher mutational frequency and were associated with disease phenotypes (e.g., SF3B1, U2AF1).