1 Department of Otolaryngology-Head and Neck Surgery, University of California, Los Angeles, Los Angeles, California, U.S.A.
2 David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, U.S.A.
3 Department of Biostatistics, National Jewish Health, Denver, Colorado, U.S.A.
4 Department of Radiology, National Jewish Health, Denver, Colorado, U.S.A.
5 Clinical Research Services, National Jewish Health, Denver, Colorado, U.S.A.
6 Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado, U.S.A.
7 Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, U.S.A.
8 Departments of Medicine and Pediatrics, National Jewish Health, Denver, Colorado, U.S.A.