Tumor-induced angiogenesis is induced by the imbalanced production of proangiogenic factors by the tumor cells, including vascular endothelial growth factor-A (VEGF), platelet-derived endothelial growth factor (PDGF), transforming growth factor (TGF)-α, angiopoietin (Ang), basic fibroblast growth factor (bFGF), fibroblast growth factor (FGF), and placental growth factor (PGF) (78, 79). The gene discussed is PGF; the disease is neoplasm.