Guest Editors Francesco Bonella Francesco Bonella is Associate Professor of Medicine and Head of the Division for Interstitial and Rare Lung Disease, Department of Pneumology, at the Ruhrlandklinik University Hospital (Essen, Germany). He received his undergraduate training and his MD from the University of Verona (Verona, Italy), and completed his PhD in ILD at the University of Essen under the guidance of Professor Ulrich Costabel. His research interests include sarcoidosis, IPF, autoimmune ILD, and pulmonary alveolar proteinosis, with a special focus on biomarkers, genetic predisposition and the application of BAL. He has acted as an investigator for major clinical trials in IPF, sarcoidosis and pulmonary alveolar proteinosis. Francesco founded EuPAPNet, the European Network for pulmonary alveolar proteinosis, and is a member of the Steering Committee of ERN-LUNG: the European Reference Network on rare respiratory diseases. He has been actively involved in the European Respiratory Society (ERS) since 2014 and was Chair of the Rare DPLD/ILD Group. Francesco is involved in a range of patient advocacy initiatives and chaired the Scientific Advisory Board of the European Idiopathic Pulmonary Fibrosis and Related Disorders Federation (EUIPFF) in 2013–2019. He has been an Executive Committee member of the World Association for Sarcoidosis and Other Granulomatous Disorders (WASOG) since 2016. Francesco is the recipient of several honours and awards, including the Sarcoidosis Research Prize presented by the German Sarcoidosis Association. He is a member of the editorial boards of the European Respiratory Journal and Chest, and is Associate Editor of Respirology. Daniel A. Culver Daniel A. Culver is the Chair of the Department of Pulmonary Medicine in the Respiratory Institute at Cleveland Clinic (Cleveland, OH, USA) and the President of WASOG. Copyright ©ERS 2022. Print ISBN: 978-1-84984-145-0. Online ISBN: 978-1-84984-146-7. Print ISSN: 2312-508X. Online ISSN: 2312-5098. https://doi.org/10.1183/2312508X.10001122 vii