1. From the Fred Hutchinson Cancer Research Center and the University of Washington School of Medicine, Seattle (J.M.G., M.M., C.A.G., M.C., J.D.M.), and the Institute of Clinical Medicine, Syntex Research, Palo Alto, Calif. (C.D.,D.F.E., W.C.B., B.D.). Address reprint requests to Dr. Goodrich at the Program in Infectious Diseases, Fred Hutchinson Cancer Research Center, 1124 Columbia St., Seattle, WA 98104.