1. Charles Wolfson Centre for Reconstructive Surgery, Royal Free Hospital, London NW3 2QG, UK
2. Department of Surgical Biotechnology, Division of Surgery & Interventional Science, University College London, London NW3 2QG, UK
3. Department of Plastic Surgery, Royal Free Hospital, London NW3 2QG, UK
4. Centre for Rheumatology, Department of Inflammation, Division of Medicine, University College London, London NW3 2QG, UK
5. Division of Medical Sciences, University of Oxford, Oxford OX3 9DU, UK