NOX4 and glioma: Moreover, recent data from our group have further expanded our knowledge around NOX4 and indicate that TGF-β or PDGF can activate NOX4-mediated ROS production which in turn activates the nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf-2)-mediated transcription and leads to higher proliferation and self-renewal of human glioma stem cells [166].