1. Institute of Pathology, University of Regensburg, 93053 Regensburg, Germany
2. Central Biobank Regensburg, University and University Hospital Regensburg, 93053 Regensburg, Germany
3. Department of Pathology, German Oncology Center, 4108 Limassol, Cyprus
4. Department of Otorhinolaryngology, Head and Neck Surgery, Medical University of Vienna, 1090 Vienna, Austria
5. Institute of Pathology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
6. Department of Oral and Maxillofacial Surgery, University Hospital Regensburg, 93053 Regensburg, Germany
7. Department of Otorhinolaryngology, University Hospital Regensburg, 93053 Regensburg, Germany