The gene dosage of Vegfr2, but not endothelial Fgfr1/2, in tumor growth and pathologic neovascularization (Fig. 6) suggests that for optimal anti-angiogenic response and to minimize toxicity to the normal vasculature, partial pharmacological blockade of VEGFR2 signaling may be more efficacious and with fewer side effects than complete inhibition of VEGFR2 in some tumor types. This evidence concerns the gene KDR and neoplasm.