MOG (92–106), mouse, rat, is a biologically active peptide corresponding to the fragment of amino acids 92 to 106 in myelin oligodendrocyte glycoprotein (MOG) from mice and rats. It is noteworthy that mice subjected to MOG (92–106)-induced experimental autoimmune encephalomyelitis exhibit substantial B cell reactivity to secondary myelin antigens. Although this MOG fragment elicits only modest T cell responses, the resultant autoimmunity is profoundly severe. The peptide demonstrates encephalitogenic properties in various species, including SJL mice, DA rats, and rhesus monkeys.