1. Cancer Research Institute, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
2. Department of Medical Lifescience, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
3. Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
4. Department of Neurosurgery, Seoul St. Mary`s Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea
5. Department of Neurosurgery, Hallym University Sacred Heart Hospital, Anyang 14068, Republic of Korea