MMP12 and asthma: Overall, Mmp12 in the lungs plays critical roles in acute pro-inflammatory allergen responses, in chronic airway remodeling, and in ECM degradation, highlighting its involvements in emphysema, asthma, and lung cancer pathogenesis (Mukhopadhyay et al., 2010; Xu et al., 2017; Shibata et al., 2018).