1 Experimental Pulmonary and Inflammatory Research, Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
2 Groningen Research Institute for Asthma and COPD, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
3 Department of Respiratory Medicine, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
4 Department of Pulmonology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.