1. Lung Cancer Center, Chonnam National University Hwasun Hospital, Gwangju 58128, Republic of Korea
2. Department of Internal Medicine, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
3. Department of Pathology, Chonnam National University Hospital, Gwangju 61469, Republic of Korea
4. Department of Thoracic and Cardiovascular Surgery, Chonnam National University Hwasun Hospital, Gwangju 58128, Republic of Korea
5. Department of Internal Medicine, Chonnam National University Hospital, Gwangju 61469, Republic of Korea