MMP9 and pulmonary emphysema: Importantly, the mRNA levels of IL-1β, TNF-α, IL-8, IRF-5, IL-18, IFN-γ, TGF-β, matrix metalloproteinase-9 (MMP-9), and MMP-12 were decreased in the FMT-treated emphysema group compared with the emphysema group (Fig. 1f).