1. Departments of Medicine and Immunology, University of Colorado Health Sciences Center, Denver, CO 80262
2. Department of Medicine, Hospital for Special Surgery-Weill Medical College, Cornell University, New York, NY 10021
3. Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
4. Department of Microbiology-Immunology, Morehouse School of Medicine, Atlanta, GA 30310