Dr Horsley is an NIHR Clinician Scientist, University of Manchester Senior Lecturer and Consultant at the Manchester Adult Cystic Fibrosis Centre.  He is Academic Lead for the CF Centre and Deputy Director of the Respiratory and Allergy Clinical Research Facility.  He graduated with a first class degree from Cambridge University and honours from Edinburgh University.  He carried out his respiratory training in Leeds and Edinburgh and completed a PhD on lung physiology at Edinburgh University with the CF Gene Therapy Consortium.  His research has focussed on the measurement of ventilation heterogeneity using inert gas multiple breath washout to assess small airways disease, and the use of lung clearance index (LCI) as a clinical and research tool.  His current work is funded by the NIHR and involves development and application of novel LCI methods in adults and children (www.lci-search.com).  He heads a research group investigating LCI technologies, clinical outcome measures in CF and clinical trials.  He has contributed to international guidelines on lung function (LCI) testing in CF and published and spoken on this topic widely.  He is also an editor of the Oxford Respiratory Medicine Library handbook on CF.