Preclinical testing demonstrated efficacy of combined mTOR and KIT inhibition in imatinib-resistant GIST.110 A phase I/II study of everolimus 2.5 mg daily and imatinib 600 mg daily, respectively, demonstrated an acceptable safety profile and potential efficacy with lengthened PFS after imatinib and sunitinib failure.111. This evidence concerns the gene MTOR and gastrointestinal stromal tumor.