1. Department of Applied Tumor Biology; Institute of Pathology; University of Heidelberg; Heidelberg Germany
2. Clinical Cooperation Unit; German Cancer Research Center; Heidelberg Germany
3. Jean-Uhrmacher Institute for Oto-Rhino-Laryngological Research; University of Cologne; Cologne Germany
4. Institute of Medical Biometry and Informatics; University of Heidelberg; Heidelberg Germany
5. Department of Otorhinolaryngology; Head and Neck Surgery, University Hospital of Cologne; Cologne Germany
6. Department of Pathology; Maastricht University Medical Center; Maastricht The Netherlands
7. Department of Otorhinolaryngology; Maastricht University Medical Center; Maastricht The Netherlands
8. Department of Otorhinolaryngology; Head and Neck Surgery, University of Giessen; Giessen Germany