1. Department of Neurosurgery, Yongin Severance Hospital, Yonsei University School of Medicine, Yongin, Korea.
2. Department of Neurosurgery, International St. Mary’s Hospital, Catholic Kwandong University College of Medicine, Incheon, Korea.
3. Department of Neurosurgery, Pusan National University Yangsan Hospital, School of Medicine, Pusan National University, Yangsan, Korea.
4. Department of Neurosurgery, Spine and Spinal Cord Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
5. POSTECH Biotech Center, Pohang University of Science and Technology, Pohang, Korea.