NOX4 and cancer: Specifically, AK2 mediates mitochondrial apoptosis through the formation of an AK2–FADD–caspase 10 complex [53, 54], whereas NOX4-mediated ROS production induces apoptosis in cancer and normal cells upon stimulation, for instance by incubation with TNF-α [55], glucose [56], or anti-cancer drugs [57, 58].