1. Cystic Fibrosis Therapeutics Development Network Coordinating Center, Department of Pediatrics, Seattle Children’s Hospital, University of Washington School of Medicine, Seattle, Washington
2. Cystic Fibrosis Foundation, Bethesda, Maryland
3. Department of Medicine and Pediatrics, Medical University of South Carolina, Charleston, South Carolina; and
4. Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, Ohio