Abraham et al. [38] evaluated the possibility of oxidative damage to red blood cells of PD patients by evaluating the activity of antioxidant enzymes, verifying that the activities of SOD, CAT, glutathione peroxidase (GSH-Px), and glucose-6-phosphate dehydrogenase (G6PD) were significantly lower in PD patients. This evidence concerns the gene CAT and Parkinson disease.