1. Upper Airways Research Laboratory; Department of Otorhinolaryngology and Head and Neck Surgery; Ghent University; Ghent; Belgium
2. Respiratory Epidemiology & Public Health; Imperial College London; London; UK
3. Department of Experimental Immunology and Department of Otorhinolaryngology; Academic Medical Center; Amsterdam; the Netherlands
4. Department of Public Health and Clinical Medicine; Occupational and Environmental Medicine; Umeå University; Umeå; Sweden
5. Department of Medical Sciences: Respiratory Medicine and Allergology; Uppsala University; Uppsala; Sweden
6. Department of Immunology, Rheumatology and Allergy; Medical University of Lodz; Lodz; Poland
7. Department of Pediatric Pneumonology and Immunology; Charité University Medical Center; Berlin; Germany
8. Centre for Allergy Research and Institute of Environmental Medicine; Karolinska Institutet; Stockholm; Sweden
9. Immunoallergology Department; Coimbra University; Coimbra; Portugal
10. Center for Applied Genomics; The Children's Hospital of Philadelphia; Philadelphia; PA; USA
11. Department of Occupational and Environmental Medicine; Odense University Hospital; Odense; Denmark
12. Department of Epidemiology; College of Medicine Medical University of Silesia; Katowice; Poland
13. Department of Otorhinolaryngology; Academic Medical Center; Amsterdam; the Netherlands