1. Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, PR. China
2. Department of Histology and Embryology, College of Basic Medicine, Jining Medical University, Jining, Shandong, 272067, PR. China
3. Department of Otolaryngology-Head and Neck Surgery, Zibo Central Hospital, Zibo, Shandong, 255036, P.R. China
4. Department of Pathology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, P.R. China
5. Department of Otolaryngology-Head and Neck Surgery, Affiliated Hangzhou First People’s Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, P. R. China