1. Department of Orthopedic Surgery, University of Düsseldorf School of Medicine, D-40210, Germany.
2. Center for Molecular Medicine, Düsseldorf D-40210, Germany.
3. Orthogen, Düsseldorf D-40210, Germany.
4. Zentrum für Molekulare Orthopädie, Düsseldorf D-40210, Germany.
5. Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.
6. Department of Orthopedics and Rehabilitation, University of Florida College of Medicine, Gainesville, FL 32610.
7. Department of Molecular Genetics and Microbiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261.
8. Center for Molecular Orthopedics, Harvard Medical School, Boston, MA 02215.