CAT and Alzheimer disease: To reveal the remodeling of redox homeostasis, we analyzed protein expression of CuZn- and Mn-superoxide dismutase (CuZnSOD and MnSOD, respectively), catalase (CAT), glutathione peroxidase (GSH-Px), glutamyl–cysteine ligase (GCL), and thioredoxin (Trx); the activity of CuZnSOD, MnSOD, CAT, thioredoxin reductase (TR), glutathione reductase (GR), and GSH-Px; and total GSH content, as well as tissue protein localization patterns of AD enzymes.