1. Department of Pulmonary Medicine, Dr. Josep Trueta University Hospital of Girona, Santa Caterina Hospital de Salt and the Girona Biomedical Research Institute, Girona, Spain
2. Department of Pulmonary Medicine, Hospital Clínic–Biomedical Research Institute August Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain; and
3. Biomedical Research Networking Center on Respiratory Diseases (CIBERES), Madrid, Spain