1. Royal Hospital for Sick Children, Glasgow
2. Hospital for Sick Children Great Ormond Street, London
3. Birmingham Clinical Trials Unit, University of Birmingham, Birmingham, UK
4. Dutch Childhood Oncology Group, The Hague, and Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
5. Leukaemia Research Cytogenetics Group, Northern Institute for Cancer Research, Newcastle University, Newcastle