His research interests include the invasive and non-invasive measurement of airway inflammation in children, in particular the use of endobronchial biopsy in the management of severe asthma, and also respiratory mass spectrometry. Thanks to the many people whom he has been lucky enough to count amongst his collaborators, he has raised more than £70 million in peer review grants and donations, including being Chief Investigator leading a £4.64 million Wellcome Strategic award (2016). He has supervised 36 MD and PhD degrees, authored more than 550 papers in peer review journals, and written more than 100 chapters in books and monographs. He has co-edited 10 books, and is currently working on the 9th edition of Kendig’s Disorders of the Respiratory Tract in Children. He has been Deputy Editor of the American Journal of Respiratory and Critical Care Medicine (the highest impact factor respiratory journal, the only Deputy Editor from outside North America), and Head of the Paediatric Assembly of the European Respiratory Society. He was the Joint Editor in Chief of Thorax, then the 2nd ranked chest journal in the world, and top-ranked outside North America, the first paediatrician to hold this post. He has been Visiting Professor overseas on ten occasions and delivered fourteen named lectures, including the 2007 Charles West Lecture at the Royal College of Physicians. He was 2008 Jonxis Medallist, University Hospital of Groningen, Netherlands.