This is the last ERS Monograph that I, Robert Bals, will handle as Editor in Chief, and I now hand over to the incoming Editor in Chief John R. Hurst. During my time as Editor in Chief, I have tried to focus on topics that are relevant to the physician at the bedside. And I feel that together with the outstanding work of the guest editors, the many authors involved and the ERS Publications Office, we have produced an excellent series of books. It has been a great pleasure and an honour to serve as ERS Monograph Editor in Chief – thank you! vi https://doi.org/10.1183/2312508X.10013019