1Department of Otorhinolaryngology/Head and Neck Surgery, University Hospital of Bonn, 53127 Bonn, Germany, 2Department of Prostate Cancer Research, Institute of Pathology, University Hospital of Bonn, SigmundFreud-Str. 25, 53127 Bonn, Germany, 3Medical Center II, University Hospital of Tuebingen, 72076 Tuebingen, Germany, 4Institute of Pathology, University Hospital of Heidelberg, 69120 Heidelberg, Germany and 5Department of Craniofacial Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA