 Imatinib is highly effective for the treatment of chronic eosinophilic leukemia (CEL) caused by the FIP1L1-PDGFRA fusion gene.     ///    "Reverse transcriptase-polymerase chain reaction and sequencing analyses revealed a FIP1L1-PDGFRA fusion transcript with FIP1L1 intron 10 fused to PDGFRA exon 12, and fluorescent in situ hybridization analysis confirmed the interstitial deletion in chromosome 4q12. "    ///    "Fortunately, the FIP1L1-PDGFRA fusion transcript had become undetectable, and imatinib treatment was stopped. "