1. Department of Neurosurgery, Soonchunhyang University Seoul Hospital, Seoul 04401, Korea
2. Department of Neurosurgery, Pusan National University Hospital, Busan 49241, Korea
3. Department of Neurosurgery, Seoul National University Hospital, Seoul 03080, Korea
4. Cancer Research Institute, Seoul National University, Seoul 03080, Korea
5. Ischemia Hypoxia Disease Institute, Seoul National University, Seoul 03080, Korea