1. Ishikawa Clinic, 263 Iwakura Mikasa-cho, Sakyo-ku, Kyoto 606-0008, Japan
2. Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
3. Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Japan
4. Department of Otolaryngology, Head and Neck Surgery, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
5. Department of Therapeutic Oncology, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
6. Department of Gastroenterology and Hepatology, Kobe City Medical Center General Hospital, 2-2-1 Minatojimaminamimachi, Chuo-ku, Kobe City, Hyogo 650-0047, Japan
7. Shiga Medical Center Research Institute, 5-4-30, Moriyama, Moriyama, Shiga 524-8524, Japan