Inhibition of MOG-specific autoreactive CD4+ T cells was shown to exert a strong protective effect in experimental autoimmune encephalomyelitis (EAE) animal model of multiple sclerosis (Kohm et al, 2002), however, selective targeting of the autoreactive CD4+ T cell population while sparing other T cells in patients with MS remains a challenging task. This evidence concerns the gene CD4 and multiple sclerosis.