U2AF1 and Thrombocytopenia: Mutations involved in the spliceosome complex (SF3B1, SRSF2, U2AF1), which are commonly mutated in MDS patients, were significantly enriched in population-based individuals with thrombocytopenia.34,35 Similarly, spliceosome mutations were enriched in older individuals with anemia compared with matched controls.7 However, the enrichment of spliceosome mutations in thrombocytopenia cases could not be explained by the presence of additional cytopenias, for instance anemia.