1 University of Munich, Department of Medicine V, LMU University Hospital, LMU Munich, Comprehensive Pneumology Center, Member of the German Center for Lung Research, Munich, Germany; juergen.behr@med.uni-muenchen.de.
2 Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States.
3 Imperial College London, 4615, National Heart and Lung Institute, London, United Kingdom of Great Britain and Northern Ireland.
4 Weill Cornell Medical College, 12295, Department of Medicine, New York, New York, United States.
5 Massachusetts General Hospital, Pathology, Boston, Massachusetts, United States.
6 Brigham and Women's Hospital, 1861, Medicine, Boston, Massachusetts, United States.
7 McMaster University, Hamilton, Ontario, Canada.
8 University of British Columbia, Medicine, Vancouver, British Columbia, Canada.
9 Louis Pradel University Hospital, Respiratory Medicine, Lyon, France.
10 Mount Sinai Medical Center, 5944, Department of Pathology, New York, New York, United States.
11 Royal Prince Alfred Hospital, Department of Respiratory Medicine, Sydney, New South Wales, Australia.
12 University of Sydney, 4334, Medical School, Sydney, New South Wales, Australia.
13 St Vincent's Hospital, Respiratory and Sleep Medicine, Sydney, New South Wales, Australia.
14 University of Chicago, Section of Pulmonary and Critical Care, Dept. of Medicine, Chicago, Illinois, United States.
15 Cedars Sinai Medical Center, Department of Medicine, Los Angeles, California, United States.
16 K U Leuven, respiratory medicine, Leuven, Belgium.
17 University of Virginia, 2358, Division of Pulmonary and Critical Care Medicine, Charlottesville, Virginia, United States.
18 University of California Davis, 8789, Pulmonary and Critical Care Medicine, Davis, California, United States.
19 Universita Cattolica del Sacro Cuore Sede di Roma, 96983, Pulmonary Medicine, Roma, Lazio, Italy.
20 University of Washington Medical Center, 21617, Division of Pulmonary and Critical Care Medicine, Seattle, Washington, United States.
21 Royal Brompton Hospital, Interstitial Lung Disease Unit, London, United Kingdom of Great Britain and Northern Ireland.