CXCL2 and pulmonary emphysema: The COPD features observed in these mice are significant increases in the chronic airway and lung cellular and cytokine/chemokine (increased TNF‐α, CXCL2, IL‐1B, keratinocytes‐derived chemokine (KC)/murine equivalent of human IL‐8) inflammation, airway remodeling and fibrosis, emphysema and impaired lung function and gas exchange compared to control mice exposed to normal air.22, 34