Considering that the identification of novel biomarkers and targets and personalized medicine are fundamental priorities for MS and since MS is an autoimmune disorder, the recognition of receptors and ligands that decrease the T cells activity can be promising for MS targeted therapy; therefore, the evaluation of the role of Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) in MS deserves particular attention [11,43]. Here, CTLA4 is linked to Autoimmunity.