KIT and neoplasm: The combination of imatinib and the anti-VEGFRs vatalanib (but not single treatments) improved the therapeutic efficacy of chemotherapy with paclitaxel in reducing the growth of mouse B16 tumor stably expressing PDGF-BB; a similar but less pronounced effect was obtained with siRNA-mediated c-kit downregulation, indicating a role of c-kit in resistance to paclitaxel (105).