FGF2 and neoplasm: Moreover, platelets also have the ability to stimulate expression of proangiogenic factors by the tumor cell.[33] Platelets have long been identified as a major source of vascular endothelial growth factor (VEGF),[37, 38] a platelet-derived growth factor (PDGF), and a basic fibroblast growth factor (bFGF), each of which promotes tumor growth.[39, 40] Activation of platelets and the release of platelet microparticles, leads to the release of a variety of proangiogenic factors.