1. Department of Pathology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
2. Special Task Force for Activating Research, Department of Pathology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand
3. Department of Oral Biology, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand
4. Department of Otolaryngology, Head and Neck Surgery, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand