1. Respiratory Medicine Department—Lung Cancer Research Group, Institute of Medical Research of Hospital del Mar (IMIM)-Hospital del Mar, Parc de Salut Mar, Barcelona Biomedical Research Park (PRBB), Barcelona, Spain;
2. Centro de Investigación en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Bunyola, Majorca, Balearic Islands, Spain; and
3. Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota