1. Department of Otolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Cheonan Hospital, Cheonan, Korea.
2. BK21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
3. Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea.
4. Airway Mucus Institute, Yonsei University College of Medicine, Seoul, Korea.
5. Research Center for Natural Human Defense System, Yonsei University College of Medicine, Seoul, Korea.
6. Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul, Korea.