1. Department of Otorhinolaryngology, Hirosaki University Graduate School of Medicine
2. Department of Otorhinolaryngology Head & Neck Surgery, Faculty of Medical Science, University of Fukui
3. Department of Otorhinolaryngology, Nippon Medical School
4. Department of Otorhinolaryngology, Osaka Habikino Medical Center
5. Department of Otorhinolaryngology and Head & Neck Surgery, Yamanashi University Hospital
6. Department of Otolaryngology, Head and Neck Surgery Graduate School of Medical Science Kanazawa University
7. Department of Otorhinolaryngology and Head and Neck Surgery, Akita University Graduate School of Medicine
8. Department of Otorhinolaryngology, Head and Neck Surgery, Hiroshima University
9. Department of Otorhinolaryngology-Head and Neck Surgery, Mie University Graduate School of Medicine
10. Division of Molecular Epidemiology, Jikei University School of Medicine