PDGFRB and Increased total eosinophil count: The t (5; 12) (q31-33; p12-13), caused eosinophilia and monocytosis or myeloid primitive ocytosis, and responded to hydroxyurea or imatinib, but was also resistant and rapidly deteriorated.7 These characteristics are believed to be due to activation of the platelet-derived growth factor receptor (PDGFRb) gene rearrangement located at chromosome band 5q31-33.