Participants undergo sputum cytology, white-light (with or without fluorescence) bronchoscopy, and endobronchial biopsies. Participants also undergo endobronchial brushings and bronchial secretion collection and possibly bronchoalveolar lavage. Collected samples are processed by hematoxylin, eosin, and immunohistochemical staining and analyzed for specific biomarkers. Unused samples are stored in the tissue bank.