Guest Editor J-F. Cordier J-F. Cordier is Professor of Respiratory Medicine at the Claude Bernard University and Head of the Department of Respiratory Medicine at Louis Pradel Heart and Lung Hospital in Lyon, France. He is also Head of the national Reference Center for Rare Pulmonary Diseases and the Rhone-Alpes ˆ Regional Competence Center for Pulmonary Hypertension. He served as the Head of the European Respiratory Society (ERS) Clinical Assembly and as President of the Societe ´ ´ de Pneumologie de Langue Franc¸aise. J-F. Cordier has been involved in the field of rare ‘‘orphan’’ diseases for many years. In 1997, he wrote an editorial which was published in the journal Le Monde, entitled ‘‘Orphan diseases: the silent exclusion’’. He participated in the preparation of the French National Plan for Rare Diseases (2008–2010), as well as the second National Plan (2011–2014), and has been involved in both committees at the French Ministry of Health. In 1993, he founded the Groupe d’Etudes et de Recherche sur les Maladies ‘‘Orphelines’’ Pulmonaires (GERM"O"P), a collaborative group of French clinical researchers investigating rare pulmonary diseases. GERM"O"P has published a number of articles on eosinophilic pneumonias, hereditary haemorrhagic telangiectasia, microscopic polyangiitis and lymphangioleiomyomatosis. He has also contributed to the description of cryptogenic organising pneumonia, pulmonary amyloidosis, idiopathic nonspecific interstitial pneumonia, and the syndrome of combined pulmonary fibrosis and emphysema. Together with S.R. Johnson he published the ERS guidelines for the diagnosis and management of lymphangioleiomyomatosis. He has been involved in the following consensus statements as a co-author: American Thoracic Society (ATS)/ERS idiopathic pulmonary fibrosis diagnosis and treatment: international consensus statement in 2000 ATS/ERS Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias in 2002 and the ATS/ERS/Japanese Respiratory Society (JRS)/ Asociacion ´ Latınoamericana ´ de Torax ´ (ALAT) statement on idiopathic pulmonary fibrosis: evidence-based guidelines for diagnosis and management in 2011. Eur Respir Mon 2011 54: v. Printed in UK – all rights reserved Copyright ERS 2011 European Respiratory Monograph ISSN: 1025-448x DOI: 10.1183/1025448x.10021411 v