1 Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy; Interventional Pulmonology Unit, Careggi University Hospital, Florence, Italy. Electronic address: s.tomassetti@gmail.com.
2 Vanderbilt University Medical Center, Nashville, TN.
3 Department of Respiratory Diseases and Allergy, Aarhus University Hospital, Aarhus, Denmark; Department of Diseases of the Thorax, G.B. Morgagni Hospital/Bologna University, Forlì, Italy.