1. From Institut Nationale de la Santé et de la Recherche Medicale (INSERM) U 320, Centre Cyceron, Caen, France (J.C.B.); Department of Neuroradiology, University of Heidelberg (Germany) (R. von K.); and Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, Calif (G.J. del Z.).