To compensate for nutrient and oxygen scarcity, tumor cells trigger the HIF signaling pathway and consequent expression of pro-angiogenic proteins, such as vascular endothelial growth factor (VEGF), angiopoietin-1/-2, platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF). The gene discussed is FGF2; the disease is neoplasm.