1. Division of Immunogenetics, Department of Pediatrics, University of Pittsburgh School of Medicine, Rangos Research Center, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania;
2. Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California;
3. Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada;
4. Department of Medicine, National Jewish Medical and Research Center, Denver, Colorado.