1. Section for Transplantation Immunology and Immunohematology, Center for Medical Research, University of Tübingen, 72072 Tübingen, Germany
2. Department of Nephrology and Rheumatology, University Hospital Göttingen, 37075 Göttingen, Germany
3. Institute for Physiological Chemistry, Münster University Hospital, 48149 Münster, Germany
4. Department of Neurology, University Hospital Tübingen, 72076 Tübingen, Germany
5. Center for Biochemistry, Department of Dermatology, and Center for Molecular Medicine, University of Cologne, 50931 Cologne, Germany
6. Department of Anatomy and Cell Biology and Faculty of Dentistry, McGill University, Montreal, Quebec H3A 2B2, Canada
7. Max Planck Institute of Biochemistry, Department of Molecular Medicine, 82152 Martinsried, Germany
8. Center for Molecular Biology of Plants, University of Tübingen, 72076 Tübingen, Germany
9. Max-Planck-Institute for Developmental Biology, 72076 Tübingen, Germany