1. Department of Thoracic Surgery, Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, China
2. Thoracic Oncology Program, Department of Surgery, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94115, USA
3. Department of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, Zhejiang 310016, China