In a chronic cigarette smoke-induced animal model, the autophagy protein LC3B and its related regulatory molecule Egr-1 increased alveolar lumen widening and, therefore, emphysema progression.[46,63] According to Hou et al,[64] porcine pancreatic elastase induces lung autophagy and promotes lung cell death and emphysema via the MAPK8 and MAPK14 pathways. The gene discussed is EGR1; the disease is pulmonary emphysema.