1. Division of Hematology, Department of Internal Medicine, Yonsei University College of Medicine, Severance Hospital, Seoul 03722, Republic of Korea
2. Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
3. Department of Pathology, Yonsei University College of Medicine, Severance Hospital, Seoul 03722, Republic of Korea
4. Department of Neurosurgery, Yonsei University College of Medicine, Severance Hospital, Seoul 03722, Republic of Korea
5. Department of Radiation Oncology, Yonsei University College of Medicine, Severance Hospital, Seoul 03722, Republic of Korea