Imatinib, however, is not selective for BCR-Abl and also inhibits the PDGFR kinase and KIT receptor tyrosine kinase, thereby expanding its therapeutic utility to other diseases, for example, gastrointestinal stromal tumors [47] or idiopathic hypereosinophilic syndrome [48]. This evidence concerns the gene ABL1 and idiopathic hypereosinophilic syndrome.