1. Department of Internal Medicine, Chungbuk National University Hospital, Cheongju, Korea.
2. Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea.
3. The Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
4. Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.
5. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.