To grow and spread, tumors need new blood vessels, a process called angiogenesis. One growth factor that causes angiogenesis has been identified - vascular endothelial growth factor or VEGF - and drugs to inhibit VEGF are already in use. But not all tumors respond to the therapy initially or over the long term. Thus new growth factors need to be identified to aid in developing the next generation of angiogenesis inhibitors. [More]