NOX4 and glioblastoma: Most recent studies have shown that Nox4 played important roles in cycling hypoxia-mediated HIF-1 activation and further promoted tumor progression in glioblastoma [10, 11], suggesting that Nox4 might be a critical mediator of radioresistance in GBM, since hypoxia is known as a major reason for the resistance of tumor cells to radiation [12].