Our understanding of the process of tumor angiogenesis has changed significantly since the
late 1970s, when vascular endothelial growth factor (VEGF) was first identified as vascular
permeability factor and later found to be the major mediator of physiologic and pathologic
angiogenesis. Since then, several additional VEGF-related ligands, VEGF receptors
(VEGFRs), and complementary/alternative pathways that regulate tumor angiogenesis have
been identified. Over the last decade, several antiangiogenic agents have been developed …