1. Department of Paediatric and Adolescent Haematology and Oncology; Great North Children's Hospital; Newcastle upon Tyne Hospitals NHS Foundation Trust; Newcastle Upon Tyne; UK
2. Clinical Trial Service Unit; University of Oxford; Oxford; UK
3. Department of Paediatric Haematology; Sheffield Children's Hospital; Sheffield; UK
4. Department of Haematology; Great Ormond Street Hospital; London; UK