Namely: (1) radiation activates HIF-1 in a solid tumor; (2) HIF-1 induces the expression of VEGF; (3) VEGF protects endothelial cells from the cytotoxic effects of radiation, and (4) the radio-protected tumor blood vessels assure the supply of oxygen and nutrients to tumour cells and promote tumour growth [10,14,24]. The gene discussed is VEGFA; the disease is neoplasm.