1. Department of Otorhinolaryngology - Head and Neck Surgery; University of Helsinki and Helsinki University Hospital; Helsinki Finland
2. Department of Otorhinolaryngology - Head and Neck Surgery; University of Turku and Turku University Hospital; Turku Finland
3. Department of Otorhinolaryngology - Head and Neck Surgery; Tampere University Hospital; Tampere Finland
4. Department of Otorhinolaryngology - Head and Neck Surgery; Kuopio University Hospital; Kuopio Finland
5. Department of Pathology, Haartman Institute; University of Helsinki; Helsinki Finland
6. Cancer and Translational Medicine Unit, University of Oulu, Medical Research Unit; Oulu University Hospital
7. Oral and Maxillofacial Diseases; University of Helsinki, and Haartman Institute; Helsinki Finland