GREATER SELECTIVITY leading to total acceptance the goal of researchers seeking new antirejection drugs for persons who receive organ transplants. At the Clinical Congress of the American College of Surgeons, held in Atlanta, Ga, experts in immunology and transplantation discussed recent laboratory developments that may one day improve clinical results. Work was presented on three different compounds—an experimental molecule, a new monoclonal antibody, and a naturally occurring substance. While each one acts differently, all of the compounds specifically block the immune response to grafted foreign tissue and, in animal studies, all have been completely successful in suppressing the rejection of transplanted hearts. Fooling the immune system into thinking that a transplanted organ self and not nonself is not an immunologist's dream, says Randall E. Morris, MD, director, Laboratory for Transplantation Immunology, Stanford University School of Medicine, Palo Alto, Calif. He adds, We're close to reality. Compound RS 61443