1. Healthcare Center, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea
2. Departments of Family Medicine, Palliative Care Center, Sungkyunkwan University School of Medicine, Seoul, Korea
3. Departments of Family Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea
4. Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea