1. Hemato-Oncology Unit, Hôpital Universitaire des Enfants Reine Fabiola; U.L.B.; Brussels Belgium
2. Department of Clinical Chemistry, Hôpital Erasme; U.L.B.; Brussels Belgium
3. Hemato-Oncology Unit; Cliniques Universitaires Saint Luc; Brussels Belgium
4. Department of Pediatrics, Hôpital Saint-Pierre; U.L.B.; Brussels Belgium
5. Department of Pediatrics; Hôpital de Jolimont; La Louvière Belgium
6. Hemato-Oncology Unit, Hôpital Universitaire Brugmann; U.L.B.; Brussels Belgium
7. Hemato-Oncology Unit, Hôpital Régional de la Citadelle; ULg; Liège Belgium
8. Laboratory of Hematology, CHU-Brugmann, Hôpital Universitaire des Enfants Reine Fabiola; U.L.B.; Brussels Belgium
9. Hemato-Oncology Unit, Hôpital Erasme; U.L.B.; Brussels Belgium