Because of partial hypoxia and lack of multi-nutritious inside the solid tumor with a diameter of more than 2–3 mm, the cancer cells secrete angiogenic factors, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF), to generate new capillaries from pre-existing blood vessels mainly via the HIF–VEGF pathway [6,8,9], thus maintaining the oxygen and nutrition supply and metabolite discharge to fit the extensive proliferation of themselves. The gene discussed is VEGFA; the disease is cancer.