FIP1L1-PDGFRA fusion genes were found in 3 of the 4 HES patients.     ///    The identification of FIP1L1-PDGFRA rearrangement is a useful molecular mark for HES diagnosis and works as the therapeutic target of imatinib.     ///    " To determine whether FIP1L1-PDGFRA fusion exists in hypereosinophilic syndrome (HES) patients, explore the relationship between FIP1L1-PDGFRA fusion and clinical phenotypes, and observe and reveal the expression of signal transducer and activator of transcription 5 (STAT(5)) in granulocytes of HES and the biological significance thereof. "    ///    "[Identification of FIP1L1-PDGFRA fusion, and expression of signal transducer and activator of transcription 5 in hypereosinophilic syndrome].. "    ///    "The expression of STAT(5) protein was upregulated in FIP1L1-PDGFRA positive HES patients, while STAT(5) protein expression was negative in HES patients without FIP1L1-PDGFRA fusion. "    ///    "Furthermore, the activation of STAT(5), a downstream signal of the FIP1L1-PDGFRA fusion, indicates that HES is a malignant clonal disease of the hematopoietic tissue.. "    ///    FIP1L1-PDGFRA fusion has a universal significance for HES.     ///    The patients with FIP1L1-PDGFRA fusion were susceptible to cardiac involvement. 