CD4 and multiple sclerosis: In previous studies, CD4+ T, CD8+ T and γδ T cells co-expressing CD56 antigen have shown enhanced cytotoxicity.32, 33, 34, 35, 36 On the other hand, CD4+ T cells co-expressing CD56 (NKT-like cells) have proved to be important mediators in autoimmune diseases such as multiple sclerosis,37 Behçet's disease38 and type-1 diabetes.34