While VEGF is the main angiogenic factor, GBM tumors often also express various other proangiogenic factors, including platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), integrins, hepatocyte growth factor/scatter factor, angiopoietins, ephrins, and interleukin-8 [67]. Here, HGF is linked to glioblastoma.