PROJECT SUMMARY/ ABSTRACT Cigarette smoking is the greatest known single risk factor for the development of lung disease, being a dominant risk for the development of both emphysema and idiopathic pulmonary fibrosis. We have assembled a team of investigators who have worked synergistically to better understand the mechanism(s) by which cigarette smoke can induce either lung fibrosis or emphysema. Our team members are leaders in the field of COPD and IPF who are most committed to better understand the mechanism(s) by which cigarette smoke can induce either fibrotic or emphysematous phenotype in the lung. During the previous years of funding support by P01 HL114501 grant entitled “Distinct and Overlapping Pathways of Fibrosis and Emphysema in Cigarette Smokers”, we have integrated the expertise of investigators from the COPD and IPF communities, spanning basic, translational and clinical researchers, to come together to tackle this important challenge. This synergistic integration among the projects and cores have been impactful and will continue to be greater than the sum of each of its component parts. We employ both Ureductionist and mechanisticU approaches by utilizing cell culture and animal models (Project 1 and Project 2), and UdiscoveryU approaches using high throughput profiling (genomics, epigenetics) methods in human lung tissues and cells (Project 3) to discover new pathway(s) mediating the fibrotic and emphysema phenotypes in cigarette smoker. Hence, a PPG mechanism has been not only critical but absolutely necessary to best address the main objective of this fundamental question at hand: How can we better understand the mechanism(s) by which cigarette smoke mediates fibrotic or emphysematous phenotype in the lung? We will attempt to reach our goals by approaches described in the following Uprojects and cores: Projects: 1) Mitochondrial and Metabolic Dysfunction in COPD and IPF 2) Differential roles of Chi3l1 and its Receptors in Pulmonary Fibrosis and COPD 3) Integrating Omics, Networks, and Functional Studies in COPD and IPF Cores: A) Administrative Core B) Respiratory Computational Discovery Core C) Clinical Biorepository Core D) Molecular Characterization Core