NOX4 and renal cell carcinoma: Our laboratory and others has identified Nox oxidases, and particularly the isoform Nox4, as a major source of ROS in renal cell carcinoma [6], [7], [8] and our group has previously demonstrated that AMP-activated protein kinase (AMPK) is a novel upstream regulator of Nox oxidase protein expression and activity [9], [10], [11].