RecruitingMechanisms of Familial Pulmonary FibrosisThis a prospective, longitudinal study of first-degree family members of patients diagnosed with familial interstitial pneumonia (FIP). FIP is the familial form of idiopathic pulmonary fibrosis (IPF), which is defined as 2 or more bloodline relatives which have a diagnosis of idiopathic interstitial pneumonia (IIP). The most common form of idiopathic interstitial pneumonia in FIP families is IPF (approximately 70%). The inheritance pattern in FIP is consistent with autosomal dominant inheritance with incomplete penetrance. Therefore, individuals in this study have approximately 50% risk of carrying a disease-associated allele. The causative gene is currently only known approximately 20% of families. The main goal of this longitudinal study is to better establish the natural history of FIP and to identify risk factors for later development of symptomatic disease. The investigators' plan is to follow these at-risk individuals with yearly questionnaires and planned in person 2 year follow-ups through age 75 or until they develop symptomatic FIP.