1. Department of Otorhinolaryngology, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China
2. Department of Otorhinolaryngology, The First Hospital of Hebei Medical University, Shijiazhuang, Hebei 050031, P.R. China
3. Department of Laboratory of Pathology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050019, P.R. China