Spire Murrayfield Hospital, 122 Corstorphine Rd, Edinburgh EH12 6UD, UK; NHS Lothian Department of Plastic Surgery, St Johns Hospital, Howden South Rd, Livingston, West Lothian EH54 6PP, UK; MRC Centre for Regenerative Medicine, 5 Little France Drive, Edinburgh, EH16 4UU, UK. Electronic address: