1. Department of Epidemiology, College of Preventive Medicine, Third Military Medical University, Chongqing, China
2. Department of Thoracic Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
3. Department of Pathology, MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI, USA
4. Health Sciences Research, Mayo Clinic College of Medicine, Rochester, MI, USA
5. Department of Respiratory Disease, Xinqiao Hospital, Third Military Medical University, Chongqing, China