1. Royal Free and University College London Medical School, London, United Kingdom;
2. Clinical Trial Service Unit, Oxford, United Kingdom;
3. Christie Hospital National Health Service (NHS) Trust, Manchester, United Kingdom;
4. Case Western Reserve University, Cleveland, OH;
5. Mayo Clinic, Rochester, MN;
6. University of Pennsylvania Medical Center, Philadelphia, PA;
7. Bristol Children's Hospital, Bristol, United Kingdom;
8. University of Glasgow and Scottish National Blood Transfusion Service, Glasgow, Scotland
9. Nottingham University Hospitals, Nottingham, United Kingdom;
10. Northwestern University Feinberg School of Medicine, Chicago, IL;
11. Rambam Medical Center and Technion, Haifa, Israel;
12. University College London Hospitals, London, United Kingdom;