Based on this observation, we hypothesised that the Sesn2 mutation would protect mice from developing emphysema after chronic exposure to cigarette smoke (an animal model that more closely mimics human COPD than does the Ltbp4S KO mouse), and that Sesn2 expression might be altered in the lungs of individuals with COPD. The gene discussed is LTBP4; the disease is pulmonary emphysema.