 Visits will involve questionnaires and various tests measuring lung function such as spirometry, forced oscillation, and methacholine challenge. Exhaled nitric oxide will be measured as an indication of inflammation. Subjects will also measure and make note of lung function at home twice daily using a peak expiratory flow meter. Two of the visits will involve fiberoptic bronchoscopy so that the investigators may collect cells and tissue samples without surgery. Another two of the visits will involve the use of high resolution computed tomography HRCT scans to indirectly evaluate disease in distant parts of the lungs. 