Given that IFN-γ exhibits many immunoregulatory properties and since MS patients were reported to be deficient in its production a small clinical trial was performed to determine whether the administration of IFN-γ would be therapeutic (Neighbour et al., 1981; Vervliet et al., 1983; Panitch et al., 1987; Panitch, 1994). The gene discussed is IFNG; the disease is myeloid sarcoma.