MMP9 and pulmonary emphysema: Regarding lung remodeling, there was an increase in the expression of MMP-9 and MMP-12 in the airways and alveolar septa, and for TGF-β only in the alveolar septa, in the overlap group (ACO) compared to the OVA and ELA groups, suggesting a potentiation of the remodeling response in the overlapping disease relative to asthma and emphysema models.