1. Department of Pathology, Gachon University Gil Hospital, Gachon University of Medicine and Science, Incheon, Korea.
2. Department of Pathology, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Department of Pathology, Konkuk University School of Medicine, Seoul, Korea.
4. Department of Occupational Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
5. Department of Pathology, Dong-A University College of Medicine, Busan, Korea.