1. Department of Biomedical Research
2. Department of Medicine, and
3. Department of Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
4. Division of Biostatistics and Bioinformatics, National Jewish Health, Denver, Colorado
5. Department of Epidemiology, Colorado School of Public Health, Aurora, Colorado; and
6. Department of Immunology and Microbiology, University Colorado Anschutz Medical Campus, Aurora, Colorado