1 Pusan National University Hospital, Pusan National University School of Medicine, Department of Otorhinolaryngology and Biomedical Research Institute, Busan, South Korea.
2 Pusan National University Hospital, Pusan National University School of Medicine, Department of Pathology, Busan, South Korea.
3 Pusan National University Hospital, Pusan National University School of Medicine, Department of Otorhinolaryngology and Biomedical Research Institute, Busan, South Korea. Electronic address: choks@pusan.ac.kr.