KDR and neoplasm: This multifunctional profile lends itself to inhibition of: tumor and endothelial cell proliferation via the Ras/Raf/MEK pathway, endothelial cell activation and proliferation via VEGFR-2, recruitment of pericytes via PDGFR-β (required for vessel stabilization and maturity), recruitment of stabilizing stromal cells to the tumor's parenchyma, as well as subsequent stimulation of stromal cell derived growth factors [5-10].