1. Division of Pulmonary, Critical Care and Sleep Disorders Medicine, Department of Medicine; University of Louisville School of Medicine; Louisville Kentucky USA
2. Laboratory of Molecular Diagnosis of Cancer, Cancer Center, West China Hospital; Sichuan University; Chengdu Sichuan Province China
3. Lung Cancer Center, West China Hospital; Sichuan University; Chengdu Sichuan Province China
4. Louisville Veterans Affairs Medical Center; Louisville Kentucky USA