FMO5 and chronic kidney disease: It is well known that ROS and reactive nitrogen species play an important role in the pathogenesis of hypertension in CKD [20]; thus, we presume that apocynin, an NADPH oxidase inhibitor, led to a decrease in BP values through the suppression of ROS generation [11,35] and the consequent reduction in peroxynitrite (−ONOO) formation [14].