Recently, large-scale sequencing projects have identified recurrent somatic mutations in certain components of the spliceosome, such as SF3B1, U2AF1, SRSF2 and ZRSR2, in several types of hematological malignancies, including myelodysplastic syndromes (MDS), other myeloid neoplasms, and chronic lymphocytic leukemia (reviewed in [2]). Here, U2AF1 is linked to myelodysplastic syndrome.