NOS2 and multiple sclerosis: It has been reported that periodontal ligament MSC-CM [176] and gingival MSC-CM [170] significantly reduced markers of oxidative stresses as SOD-1, iNOS, and COX-2, in an in vitro model of multiple sclerosis and together with their immunomodulatory and antiapoptotic properties significantly reduced neural cells' death [170, 176].