Furthermore, the expression of vascular endothelial growth factor (VEGF), Galectin-1, Sphingosine kinase 1, SKP2, P16INK4A, hypoxia, and cancer stem cells (CSCs) may have a major influence on the survival of patients treated with definitive radiotherapy [4,5,6,7,8,9]. The gene discussed is VEGFA; the disease is cancer.