MMP-2 activity was also increased in BAL during AE-COPD, which is in good agreement with previous studies showing that there is increased immune-reactivity for MMP-2 in the lungs of patients with COPD, mainly in alveolar macrophages and airway epithelial cells [28] and that there is increased expression and activity of MMP-2 in the lungs and sputum of patients with COPD [29]. The gene discussed is MMP2; the disease is chronic obstructive pulmonary disease.