Lower reduced glutathione (GSH) [27], altered activities of antioxidant enzymes, such as glutathione peroxidase (GPx) and glutathione reductase (GR) [27,28], or increased oxidative damage of lipids, proteins, and DNA [27,29,30,31], have been described in the brains of advanced-stages PD patients. Here, GSR is linked to Parkinson disease.