1. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Thoracic and Cardiovascular Surgery, Yonsei University College of Medicine, Seoul, Korea.
3. Department of Pathology, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, Ewha Women's University College of Medicine, Seoul, Korea.
5. The Institute of Chest Diseases, Yonsei University College of Medicine, Seoul, Korea.
6. Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
7. Cancer Metastasis Research Center, Yonsei University College of Medicine, Seoul, Korea.