Upregulation of JAK2, STAT3, and P-STAT5 proteins was shown in 3 FIP1L1-PDGFRA fusion gene positive HES patients, while all of these proteins were not expressed in one case of FIP1L1-PDGFRA negative HES.     ///    "Retrospective reverse transcription polymerase chain reaction (RT-PCR) analysis of FIP1L1-PDGFRA was performed and the expressions of JAK2, STAT3 and P-STAT5 were detected by western blotting before treatment and 10, 30, and 60 days after the beginning of treatment. "    ///    "observe the dynamic change of the clinical phenotype and hematological response, the expression of janaus kinase/signal transducer and activator of transcription (JAK/STAT) protein or FIP1L1-PDGFRA mRNA in one HES patient treated with low-dose imatinib. "    ///    The amount of FIP1L1-PDGFRA transcripts in peripheral blood granulocytes was significantly decreased in 30 days after therapy and turned negative 60 days after therapy.     ///    "The granulocytes of peripheral blood of 4 HES patients, including 3 FIP1L1-PDGFRA positive cases and 1 negative case, were collected. "    ///    "Low-dose imatinib, that induces complete hematological and molecular genetic remission, exerts significant effects on FIP1L1-PDGFRA positive HES.. "