1 The Royal London Hospital, Barts Health NHS Trust, The Blizard Institute, Queen Mary University of London, London, UK. Electronic address: g.pafitanis@qmul.ac.uk.
2 Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK.
3 UMF Carol Davila Bucharest, Bucharest, Romania; Grigore Alexandescu Children's Hospital, Bucharest, Romania; Great Ormond Street Hospital, London, UK.
4 The Royal London Hospital, Barts Health NHS Trust, The Blizard Institute, Queen Mary University of London, London, UK.