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.