1. Department of Head and Neck Surgery National Hospital Organization Kyushu Cancer Center Fukuoka Japan
2. Department of Otorhinolaryngology Graduate School of Medical Sciences Kyushu University Fukuoka Japan
3. Department of Anatomic Pathology Graduate School of Medical Sciences Kyushu University Fukuoka Japan
4. Department of Surgery Kyushu University Beppu Hospital Beppu Oita Japan
5. Laboratory of Molecular Medicine Human Genome Center The Institute of Medical Science The University of Tokyo Tokyo Japan