1. Immunology Program and the Rheumatology Division, Department of Medicine and the Department of Pathology, the Center for Arthritis and Related Diseases, and the Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, Missouri 63110
2. Unite de Biologie Moleculaire du Gene, Institut National de la Santé e de la Recherche Médicale, U277, Institut Pasteur, 75015 Paris, France