Patients presenting with eosinophilia-associated myeloproliferative neoplasm who lack overexpression of PDGFRA or PDGFRB have been imatinib-responsive [6], emphasizing that it is reasonable to begin a therapeutic trial with tyrosine kinase inhibitors in symptomatic patients pending further gene fusion characterization. Here, PDGFRB is linked to Increased total eosinophil count.