1. Interdisciplinary Group Stem Cell Biology and Transplantation Unit, Medical Department I, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
2. Stem Cell Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK
3. Division of Oncology, University of Modena and Reggio Emilia, 41100 Modena, Italy
4. Institute of Transfusion Medicine and Transplantation Immunology, University of Münster, Münster, Germany
5. Stem Cell Biology and Cellular Engineering, Helmholtz Institute for Biomedical Technology, RWTH Aachen University Medical School, 52074 Aachen, Germany