1. From the Department of Pathology, Emory University (J.M.C., N.K., R.L.S., J.W.A., K.M.D., H.Z., K.E.B.), Atlanta, Ga; Howard Hughes Medical Institute, Eccles Institute of Human Genetics, University of Utah (M.R.C.), Salt Lake City; and Institut National de la Santé et de la Recherche Medicale Unit 36, College de France (P.C.), Paris.