Lysates of platelets and also growth-promoting substances isolated from platelets, such as epidermal growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor β (TGF-ß) or vascular endothelial growth factor A (VEGF-A) can promote and maintain the growth of both tumor cells and primary cells in vitro (17–19). The gene discussed is EGF; the disease is neoplasm.