1. Department of Pathology, Royal College of Surgeons of England, 35-43 Lincoln's Inn Fields, London WC2A 3PN, UK
2. Animal Care Unit, Royal College of Surgeons Research Establishment, West Hill, Downe, Orpington, Kent BR6 7JJ, UK
3. United Medical & Dental Schools of Guy's & St Thomas's Hospitals, London Bridge, London SE1 9RT, UK