NOX4 and diabetes mellitus: Although further investigations are required to verify whether TRPC6-mediated Ca2+ influx by NOX4-derived ROS evoked by Ang II contributes to the downregulation of MYH9, in this study, we suggest that elevated Ang II in diabetes induces MYH9 downregulation through TRPC6 activation-mediated Ca2+ influx by NOX4-derived ROS.