that has been made in the past decade with particular focus on our recent understanding of the mechanistic heterogeneity, using analysis of various ‘omics platforms and analytical methods applied to well-defined asthma cohorts. How these advances have led to improved management targets is emphasised. The final chapter of the Monograph looks to the future, providing a summary of what we might be expecting to occur in the next decade of severe asthma. We are of the opinion that the advances made in the next decade will result in better targeted treatments for selected groups and may pinpoint the actual causes of severity of asthma. Finally, several clinical cases of severe asthma are presented to obtain an appreciation of the clinical spectrum of the problem. This book brings together the clinical and scientific expertise of those currently working to solve the problem of severe asthma, with chapters written by experts from around the world to ensure a truly international spirit of collaboration. It should appeal to those involved in the management of severe asthma patients, as well as to those seeking to improve quality of life and to those aiming find ways of controlling this chronic disease. We would like to thank all of the authors of this Monograph for dedicating part of their busy schedule to writing these chapters. Severe asthma can have such a tremendous impact on the lives of patients. We would therefore like to dedicate this book to our patients, who have helped us focus on their greatest unmet need: to find new ways to control asthma. We hope that this Monograph will provide some hope for the future. References 1. Chung KF, Bel EH, Wenzel SE. Introduction. In: Chung KF, Bel EH, Wenzel SE. Difficult-to-Treat Severe Asthma (ERS Monograph). Sheffield, European Respiratory Society, 2011 pp. vii–ix. 2. Chung KF, Wenzel SE, Brozek JL, et al. International ERS/ATS guidelines on definition, evaluation and treatment of severe asthma. Eur Respir J 2014 43: 343–373. Disclosures: K.F. Chung reports receiving the following, outside the submitted work: grants and personal fees from GlaxoSmithKline for attending an advisory board meeting personal fees from AstraZeneca and Novartis for attending an advisory board meeting and a speakers’ bureau grants and personal fees from Merck for attending a speakers’ bureau and personal fees from Boehringer Ingelheim and TEVA for attending an advisory board meeting. E. Israel reports receiving the following, outside the submitted work. Personal fees for consultancy from AstraZeneca, Novartis, Regeneron Pharmaceuticals, TEVA Specialty Pharmaceuticals, Bird Rock Bio, Nuvelution Pharmaceuticals, Vitaeris, Inc., Sanofi Genzyme, Merck, Entrinsic Health Solutions, GlaxoSmithKline, Pneuma Respiratory, 4D Pharma, Sienna Biopharmaceutical, Equillium and Genentech. Research grants from Boehringer Ingelheim and TEVA for a drug contributed to the NIH AsthmaNet SIENA Study. A research grant from GlaxoSmithKline for a drug contributed to NIH AsthmaNet BARD, Microbiome and INFANT Studies. A research grant from Merck for a drug contributed to NIH AsthmaNet INFANT and SIENA Studies. A research grant from Sunovion for a drug contributed to NIH AsthmaNet VIDA Study. Research grants from Genentech, Sanofi, Boehringer Ingelheim, Novartis and AstraZeneca for a multicentre study. A research grant from TEVA Specialty Pharmaceuticals for a drug contributed to PCORI-PREPARE Study. P.G. Gibson reports receiving grants and personal fees from AstraZeneca, GlaxoSmithKline, Novartis and Sanofi, during the conduct of the study. x https://doi.org/10.1183/2312508X.10019419