1. Department of Orthopaedic Surgery, Yonsei University College of Medicine, Seoul, South Korea.
2. Brain Korea 21 Plus Project for Medical Sciences, Yonsei University College of Medicine, Seoul, South Korea.
3. Department of Internal Medicine, Brody School of Medicine at East Carolina University, Greenville, North Carolina.
4. Severance Biomedical Science Institute, Yonsei University College of Medicine, South Korea.