Potential sources of excessive ROS in hypertension include nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, mitochondria, cyclooxygenase 1 and 2, cytochrome P450 epoxygenase, xanthine oxidase, endothelium-derived NO synthase, and transition metals [47]. This evidence concerns the gene PTGS1 and hypertensive disorder.