Morris et al. [92] described an interesting mechanism regulating MMP-12 activity, showing that Itgb6-null mice lacking the β-subunit of the αvβ6 integrin, an integrin abundantly expressed by bronchiolar and alveolar epithelial cells, developed spontaneous age-related MMP-12-dependent emphysema. The gene discussed is MMP12; the disease is pulmonary emphysema.