1. Endocrinology
2. Pituitary Tumor Clinic, Institute of Endocrine Research
3. Brain Korea 21 Project for Medical Science, Severance Hospital Integrative Research Institute for Cerebral and Cardiovascular Diseases, Yonsei University College of Medicine, Seoul, Korea
4. Endocrinology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
5. Neurosurgery, Yonsei Brain Research Institute, Seoul, Korea