The International Working Group on Prognosis of MDS (IWG-PM) recently proposed diagnostic criteria for SF3B1 as a separate entity in MDS, including (a) cytopenia as defined by standard hematologic values, (b) somatic SF3B1 mutations, (c) morphologic dysplasia (with or without RS), and (d) bone marrow blasts <5% and peripheral blood blasts <1%. Here, SF3B1 is linked to myelodysplastic syndrome.