1. Department of Medical Biosciences/Pathology, Umeå University, SE - 901 85 Umeå, Sweden
2. RECAMO, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
3. Department of Clinical Sciences/ENT Umeå University, SE - 901 85 Umeå, Sweden
4. Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, 75010 Paris, France
5. Department of Surgical Sciences/ENT, Uppsala University, 752 36 Uppsala, Sweden