This report discusses some of the papers presented during the 2nd T Cell Autoimmunity in MS Workshop held in Perugia on November 26-28, 1992. The 'trait d'union' of the meeting was the awareness that recent studies have failed to uncover clear-cut differences in T cell reactivity to autoantigens between patients with multiple sclerosis and healthy individuals. Hence, new strategies have been proposed to try to distinguish between 'pathological' autoimmunity in patients and 'natural' autoimmunity in healthy individuals. Furthermore, the studies have been extended to new potential autoantigens (myelin constituents other than myelin basic protein, superantigens, heat shock proteins) and new susceptibility genes such as those coding for transport-associated proteins (Tap-1 and Tap-2).