1. Bone Marrow Transplantation, University Hospital Eppendorf, Martinistraße 52, 20251 Hamburg, Germany.
2. Institute for Anatomy II: Experimental Morphology, University Hospital Eppendorf, Martinistraße 52, 20251 Hamburg, Germany.
3. Department of Hematology, Hemostaseology, and Oncology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
4. Institute of Cellular and Molecular Pathology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
5. Division of Experimental Hematology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229–3039, USA.