Many crucial studies on the pathogenesis and possible treatments of MS have been carried out using a mouse model of autoimmune CNS disease that in many ways mimics MS, experimental autoimmune encephalomyelitis (EAE) induced by immunization with various neuronal antigens such as myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP), and proteolipid protein (PLP) (3–7). The gene discussed is MOG; the disease is myeloid sarcoma.