1. Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin and
2. Berlin Institute of Health at Charité – Universitätsmedizin Berlin, Berlin, Germany;
3. German Center for Lung Research, Associated Partner, Berlin, Germany;
4. Great Ormond Street Hospital for Children, London, United Kingdom;
5. Hospital Universitari Vall d’Hebron, Barcelona, Spain;
6. Southampton Children's Hospital, Hampshire, United Kingdom;
7. University Children’s Hospital, Zurich, Switzerland;
8. Hospital Clinico Universitario Virgen de la Arrixaca, Murcia, Spain;
9. Schneider Children’s Medical Center of Israel, Petah Tikva, Israel;
10. Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel;
11. Copenhagen University Hospital, Rigshospitalet, Denmark;
12. The Hospital for Sick Children, Toronto, Ontario, Canada;
13. Hôpital Femme Mère-Enfant, Hospices Civils de Lyon, Bron, France;
14. The Children’s Hospital at Westmead, Sydney Children’s Hospital Network, Sydney, Australia;
15. Universitätsklinikum Essen, Klinik für Kinderheilkunde III, Essen, Germany;
16. Vertex Pharmaceuticals Incorporated, Boston, Massachussetts;
17. Queensland Children’s Hospital, University of Queensland, Queensland, Australia;
18. National Heart and Lung Institute, Imperial College London, London, United Kingdom;
19. Royal Brompton and Harefield Hospitals, part of Guy’s and St Thomas’ NHS Trust, London, United Kingdom; and
20. European Cystic Fibrosis Society Lung Clearance Index Core Facility, London, United Kingdom