CAT and atherosclerosis: Indeed, an imbalance between the activity of pro-oxidant systems (e.g., NADPH oxidase (NOX), mitochondrial respiratory chain, lipoxygenase and xanthine oxidase) and antioxidant enzymes (e.g., superoxide dismutase (SOD), glutathione peroxidase, catalase (CAT), thioredoxin peroxidase, paraoxonase and heme oxygenase), leading to increased generation of reactive oxygen species (ROS), is implicated in the initiation and progression of atherosclerosis [3].