Idiopathic pulmonary fibrosis is one of a collection of severe lung diseases that lead to abnormal inflammation and scarring of the lungs. The accumulation of scar tissue in the lung destroys normal lung tissue and results in the symptoms associated with this disease. The cause of the disease is currently unknown. In this study, we are attempting to determine if there are specific genetic traits that might explain why patients have developed pulmonary fibrosis. We are also attempting to determine if specific genetic traits account for differing patterns of inflammation and scar tissue that has formed in the patient's lungs. The purpose of this research is to identify genes that control the processes of lung inflammation, lung scarring, and lung repair. As more information becomes available, we will also conduct studies of additional genes that are found to be involved in this disease process.