To the Editor:The presence of FIP-1-like-1-platelet-derived growth factor receptor-α (FIP1L1-PDGFRA,F/P) fusion gene accounts for approximately 23％ (3％-56％) of all eosinophilias.[1] From 2008,the World Health Organization (WHO) classification redefined this disease as myeloid/lymphoid neoplasms with eosinophilia and PDGFRA rearrangement, now constituting a distinct type of hematopoietic disorders.F/P fusion is a tyrosine kinase and is therefore sensitive to tyrosine kinase inhibitors (TKIs).TKIs are recommended as the first-line therapy in the treatment of myeloid/lymphoid neoplasms with eosinophilia and PDGFRA rearrangement by the WHO guidelines.[2]