NOX4 and ovarian carcinoma: In order to explore the role of NOX4 and HIF-1α in the radiation therapy of ovarian cancer, OVCAR3 cells were transfected with shNOX4 or control shNC vector; at 48 h after transfection, cells were irradiated with 6MV X-ray linear accelerator at doses of 0 Gy, 2 Gy, 4 Gy and 6 Gy.