In this review, we discuss the recently updated morphologic and molecular diagnostic criteria of MDS/MPN, focusing more on CMML, myelodysplastic/myeloproliferative neoplasm with neutrophilia (named yet aCML in the ICC), and MDS/MPN with SF3B1 mutation and thrombocytosis/MDS/MPN with ring sideroblasts and thrombocytosis. This evidence concerns the gene SF3B1 and myelodysplastic syndrome.