Receptors for VEGF have central roles in vasculogenesis and angiogenesis and thus serve as targets for cancer therapy. Cediranib is a potent inhibitor of VEGF receptor tyrosine kinases, including VEGFR1, 2, and 3 (IC50s = 5, 1, and 3 nM, respectively). It also potently inhibits a variety of other receptor and non-receptor tyrosine kinases, including several in the platelet-derived growth factor, fibroblast growth factor, and endothelial growth factor receptor families. Cediranib blocks tubule formation by human umbilical vein endothelial cells in vitro and prevents angiogenesis as well as xenograft tumor growth in vivo. Because of these effects, cediranib has potential use in a range of cancers.