ERS | monograph Preface John R. Hurst It is a privilege to introduce this latest ERS Monograph, on Lung Stem Cells in Development, Health and Disease. The mission of the European Respiratory Society is to promote lung health in order to alleviate suffering from disease and drive standards for respiratory medicine globally. Science, education and advocacy are at the core of that mission. But it is only through development in basic science that we will make transformational discoveries to improve lung health. It has been an ambition of the Editorial Board to commission Monographs to address topics in respiratory science, not just clinical reviews, and this is the first of a new series. I am particularly pleased, therefore, to see publication of a Monograph that will educate and inform you about one of the most exciting areas of respiratory science: lung stem cells. I warmly congratulate the Guest Editors, Marko Z. Nikolić and Brigid L.M. Hogan on commissioning and collating a comprehensive, state-of-the-art series of review articles from a diverse group of authors. It has been a pleasure to work with them both, and to see their proposal through to publication. Credit too, to the chapter authors: not just for the quality of their reviews, but also for sharing their enthusiasm and passion for respiratory science, which I hope will inspire others to pursue such avenues of research. What will you find here? I can do no better than quote the Guest Editors’ introduction: “This Monograph brings together information about the different classes of stem cells present in both the developing and adult lung: where they are found, how they function in homeostasis and pathologic conditions, the mechanisms that regulate their behaviour, and how they may be harnessed for therapeutic purposes.” Please, read on, I assure you that you will not be disappointed. Disclosures: J.R. Hurst reports receiving grants, personal fees and non- financial support from pharmaceutical companies that make medicines to treat respiratory disease. This includes reimbursement for educational activities and advisory work, and support to attend meetings. Copyright ©ERS 2021. Print ISBN: 978-1-84984-133-7. Online ISBN: 978-1-84984-134-4. Print ISSN: 2312-508X. Online ISSN: 2312-5098. https://doi.org/10.1183/2312508X.10002521 vii