Translocations of the platelet-derived growth factor receptor (PDGFR) gene are identified in a number of myeloid neoplasms, which are included in the 2008 World Health Organization classification of hematolymphoid tumors as myeloid and lymphoid neoplasms with eosinophilia and abnormalities of platelet-derived growth factor receptor alpha (PDGFRA), platelet-derived growth factor receptor beta (PDGFRB), and fibroblast growth factor receptor 1 (FGFR1). The gene discussed is FGFR1; the disease is Increased total eosinophil count.