ROS molecules reportedly damage lipids, proteins, and DNA.4,5 In particular, ROS are detrimental for mitochondria and endoplasmic reticulum (ER), and dysfunction of these organelles is linked to elevated ROS.6 Several alterations in mitochondrial protein functions and structures have been described in the AD brain.7 Additionally, the AD brain reportedly exhibits reductions in several protective antioxidative proteins such as superoxide dismutase (SOD), catalase, and peroxiredoxins.5 SOD is a mitochondrial enzyme that can neutralize superoxide radicals to protect mitochondria. Here, CAT is linked to Alzheimer disease.