MATERIALS AND METHODS: Seeking to improve efficacy against otherwise intractable end-stage pancreatic islet tumors, two << receptor tyrosine kinase >> inhibitors, imatinib and [[ SU11248 ]], were used to disrupt PDGFR-mediated pericyte support of tumor endothelial cells in concert with maximum-tolerated dose (MTD) or metronomic chemotherapy and/or VEGFR inhibition.