MMP12 and asthma: In the HDM-induced asthma model, compared to air controls, we found that in utero air plus HDM treatment upregulated Mmp12 gene expression by 1.9-fold and of MMP12 protein by 1.4-fold, while in utero SHS plus HDM treatment up-regulated Mmp12 gene expression by 5.7-fold and of MMP12 protein by 7.2-fold (Figures 14C,D).