1. Division of Respiratory Diseases, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan
2. Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
3. Department of Respiratory Medicine, Faculty of Life Science, Kumamoto University, Kumamoto, Japan
4. Division of Chest Diseases, Department of Surgery, Jikei University School of Medicine, Tokyo, Japan
5. Department of Pathology, University of California, San Francisco, San Francisco, CA, USA