1. M. Hahne, M. Schröter, P. Schneider, T. Bornand, J. Tschopp, Institute of Biochemistry, University of Lausanne, CH-1066 Epalinges, Switzerland.
2. D. Rimoldi, P. Romero, M. Schreier, J.-C. Cerottini, Ludwig Institute of Cancer Research, Lausanne branch, University of Lausanne, CH-1066 Epalinges, Switzerland.
3. L. E. French, Department of Dermatology, University of Geneva, Medical School, CH-1211 Geneva 4, Switzerland.
4. A. Fontana, Clinical Immunology, Department of Internal Medicine, University Hospital, CH-8044 Zürich, Switzerland.
5. D. Lienard, Centre Pluridisciplinaire d'Oncologie, CHUV, CH-1011 Lausanne, Switzerland.