Oxidative stress has been found to be one of the molecular causes of multiple sclerosis. Brain cells are populated with maximum concentration of antioxidant glutathione. Under the condition of oxidative stress, glutathionylation of brain cell proteins occur. In this project, we are trying to profile glutathionylation of brain cell proteins by looking at the proteomics profile of cerebrospinal fluid as the blood-brain barrier allows brain cell proteins to come to the cerebrospinal fluid.