FGFR1 and Increased total eosinophil count: As the spectrum of malignancies associated with this rearrangement expanded, the 2008 WHO classification developed a category for these neoplasms, “Myeloid and lymphoid neoplasms associated with eosinophilia and abnormalities of PDGFRA, PDGFRB, or FGFR1 [8]”.