The representative proteins Ku70 and Ku80 (NHEJ pathway), and BRCA1 and BRCA2 (HR pathway) were significantly decreased, suggesting that DNA repair pathways plays an important role in the radioresistance of NPC, and VEGF silencing can weaken DNA repair and increase DNA DSB to induce radiation sensitivity in NPC cells. This evidence concerns the gene BRCA2 and nasopharyngeal carcinoma.