COPD is a disease in which the lung airways are damaged and partly obstructed, making it difficult to breathe. There is no cure for this disease, and it is the fourth leading cause of death in the United States. Symptoms include coughing, excess mucus production, shortness of breath, wheezing, and chest tightness. The most common risk factor for developing COPD is cigarette smoking; however, only 15% to 20% of smokers are diagnosed with COPD in their lifetimes, suggesting that some smokers are more prone to developing COPD than others. Elastin, a protein found in the tissues surrounding the lung airways and in the alveolar walls of the lung, is essential for healthy lung function. As elastin breaks down, lung damage can occur, potentially leading to COPD. It is thought that some people may be genetically predisposed to elastin damage by cigarette smoke, thus accounting for the select group of smokers affected by COPD. This study will examine the ways in which elastin defects contribute to the development of COPD. Researchers will examine whether genetic variations play a role in altering elastin function and in influencing health outcomes in people with COPD.