1. Klinik für Kinder- und Jugendmedizin, Kinderzentrum Bethel, Evangelisches Krankenhaus Bielefeld GmbH, Akademisches Lehrkrankenhaus der Universität Münster, Bielefeld, Germany
2. Department of Pulmonology and Allergy, University Hospital Carl Gustav Carus, Technical University of Dresden, Dresden, Germany
3. Pediatric Asthma Research Program, Children’s Hospital Colorado, Breathing Institute, Department of Pediatrics, Section of Pulmonary Medicine, Aurora, CO, USA
4. University of Colorado School of Medicine, Aurora, CO, USA