1. Molecular/Cancer Biology Laboratory and Ludwig Institute for Cancer Research, BiomedicumUniversity of Helsinki and Helsinki University Central Hospital 00014 Helsinki Finland
2. Department of OtorhinolayngologyUniversity Central Hospital FIN‐00014 Helsinki Finland
3. Department of PathologyHaartman InstituteUniversity of Helsinki
4. Institute of Molecular BiologyUniversity of Zurich 8057 Zurich Switzerland
5. A. I. Virtanen Institute and Department of MedicineUniversity of Kuopio 70211 Kuopio Finland
6. Department of PathologyUniversity of Vienna 1090 Vienna Austria