1. Doherty, P. C., Blanden, R. V., and Zinkernagel, R. M., Transplant. Rev., 29, 89–124 (1976).
2. Schrader, J. W., Henning, R., Milner, R. J., and Edelman, G. M., in XLI Cold Spring Harb. Symp. quant. Biol. (in the press).
3. Shearer, G. M., Rehn, T. G., and Garbarino, C. A., J. exp. Med., 141, 1348–1346 (1975).
4. Gomard, E., Duprez, V., Henin, Y., and Levy, J. P., Nature, 260, 707–709 (1976).
5. Pfizenmaier, K., Starzinksi-Powitz, A., Rodt, H., Röllinghoff, M., and Wagner, H., J. exp. Med., 143, 999–1004 (1976).