Multilineage involvement of the fusion gene in patients with FIP1L1/PDGFRA-positive hypereosinophilic syndrome..     ///    " Myeloproliferative hypereosinophilic syndrome (MHES) is a disorder characterised by male predominance, marked eosinophilia, splenomegaly, tissue fibrosis, elevated serum tryptase and the presence of the FIP1L1/PDGFRA fusion gene in peripheral blood mononuclear cells. "