1. From INSERM 558, Toulouse, France (JA, JBR, BC, and JF); the Institute of Molecular Medicine, I2MR, IFR 31, Toulouse, France (RB and PDC); the Service de Biochimie, INSERM U 563, CHU Toulouse, France (JF); and INSERM U 626, Marseille, France (MCA)