It has been reported that primary and secondary mutations of KIT usually occur in the same allele but not in two alleles respectively in relapsed GISTs after Imatinib treatment failure [14, 17, 33], which indicates that the KIT protein carries both primary mutation and secondary mutation in the relapsed tumor, we therefore established Ba/F3 cells stably expressing wild-type KIT and KIT mutants (Fig. 1a). This evidence concerns the gene KIT and neoplasm.