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