FGF2 and neoplasm: At the tumor site, hypoxia induces tumor cells and stromal cells to secrete a variety of pro-angiogenic factors, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and matrix metalloproteinase (MMP) (82), leading to vascular proliferation, and the abnormally proliferating vessels provide tumor development providing nutrients for tumor development.