Introduction - key molecular events in the induction and expression of the immune response, A. Warrens and R. Lechler; self non-self discrimination by the immune system, C. Sharrock; the use of cytokines and their receptors to monitor and manipulate the immune response, M.J. Dallman and G.J. Clark; tolerance to alloantigens, K.J. Wood; tolerance induced by soluable antigens, K. Gilbert, et al; molecular intervention in the therapy of autoimmune disease, D. Wraith and A. Cooke; monoclonal antibodies and immune intervention, S. Zamvil, et al; mode of action of immunosuppressive drugs with particular response to the molecular basis of macrolide-induced immuno-suppression, A.W. Thomson, et al; approaches to the design of immunosuppressive agents, A.C. Allison; conclusion, A.W. Thomson.