1. Department of Pediatrics and Cystic Fibrosis Center, Hadassah-Hebrew University Medical Center, Mount Scopus, Jerusalem, Israel
2. European Cystic Fibrosis Society Lung Clearance Index Core Over Reading Centre, London, United Kingdom
3. National Heart and Lung Institute, Imperial College London, London, United Kingdom
4. Royal Brompton & Harefield National Health Service Foundation Trust, London, United Kingdom
5. Vertex Pharmaceuticals Inc., Boston, Massachusetts
6. Vertex Pharmaceuticals (Europe) Ltd., London, United Kingdom