Dr Waller is a consultant in cystic fibrosis, bronchiectasis and respiratory medicine at King’s College Hospital, London, and an Honorary Senior Lecturer at King’s College London. Dr Waller is both CF clinical lead and lead for CF clinical research at King’s. His training includes a CF Trust Fellowship at the Royal Brompton Hospital. During his research at the National Heart and Lung Institute (Imperial College London), he developed an interest in the electrophysiology of the CF airway using nasal potential difference measurement. Dr Waller’s clinical interests include advanced CF diagnostics. He is a member of the European CF Society’s Difficult CF Diagnostic Network Working Group. In partnership with the Royal Brompton Hospital, he received a grant to set up intestinal current measurement as a new assay in their difficult CF diagnosis service and explore the utility of intestinal organoids in assessing CFTR function in people with incomplete CFTR function.