1 University of Groningen, Department of Pulmonology, Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, 9700 RB Groningen, Netherlands. Electronic address: d.s.postma@umcg.nl.
2 University of Groningen, Department of Pulmonology, Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, 9700 RB Groningen, Netherlands.
3 Department of Pulmonology, Leiden University Medical Center, Leiden, Netherlands.
4 University of Groningen, Department of Pharmacokinetics, Toxicology, and Targeting, Groningen, Netherlands.
5 Department of Pulmonary Diseases, STZ Center of Excellence for Asthma & COPD, Sint Franciscus Gasthuis, Rotterdam, Netherlands.
6 University of Groningen, Department of Pathology and Medical Biology, University Medical Center Groningen, Groningen, Netherlands.
7 University of Groningen, Department of Respiratory Medicine, Amsterdam, Academic Medical Centre, University of Amsterdam, Netherlands.