Perhaps the most convincing evidence to support a pathogenic role of IFNγ in CNS autoimmune disease was derived from an open-label, randomized clinical trial, in which 18 patients with MS received 1 μg, 30 μg, or 1000 μg of recombinant IFNγ i.v. twice a week for four weeks [30]. This evidence concerns the gene IFNG and autoimmune disease.