PDGFRB and myeloproliferative neoplasm: Proliferative disorders associated with myeloid cells including the granulocytic, monocytic/macrophage, erythroid, megakaryocytic, and mast cells have been grouped under 5 broad categories: (1) myeloproliferative neoplasms (MPN), (2) myeloid and lymphoid neoplasms associated with eosinophilia and abnormalities of platelet derived growth factor receptor (PDGFR) or fibroblast growth factor receptor (FGFR), (3) myelodysplastic/ myeloproliferative neoplasms (MDS/MPN), (4) myelodysplastic syndrome (MDS) and, (5) Acute myeloid leukemia and related neoplasms.