1. Department of Pulmonology, University Hospital of Galdakao-Usansolo, Galdakao, Bilbao, Spain
2. Department of Pneumology, Hospital Clinic of Barcelona, Barcelona, Spain
3. August Pi i Sunyer Biomedical Research Institute—IDIBAPS, University of Barcelona, Barcelona, Spain
4. Biomedical Research Networking Centers in Respiratory Diseases (CIBERES), Barcelona, Spain
5. Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain