1. Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland.
2. EBMT Activity Survey Office, University Hospital Basel, Basel, Switzerland.
3. Division of Oncology, Department of Medical and Surgical Sciences for Children & Adults, University of Modena and Reggio Emilia, Modena Policlinic, Modena, Italy.
4. UMC Utrecht, Orthopaedics, Utrecht, Netherlands.