In animal models of MS (experimental autoimmune encephalomyelitis, EAE) a well-known target structure is myelin oligodendrocyte glycoprotein (MOG) (13), a protein comprising 245 amino acids that is exclusively expressed on the outermost surface of the myelin sheath and oligodendrocyte plasma membrane in the CNS, and which is easily accessible by a humoral immune reaction (14, 15). Here, MOG is linked to myeloid sarcoma.