ACE2 and pulmonary fibrosis: In a model for pulmonary fibrosis, Uhal et al. showed that ACE-2 mRNA and activity were decreased in the lungs of bleomycin-treated rats and C57-BL6 mice similar to ACE-2 decrease in pulmonary fibrosis patients.12 In mice exposed to low doses of bleomycin, lung collagen accumulation was enhanced by intratracheal administration of either ACE-2-specific small interfering RNAs (siRNAs) or the peptide DX(600), a competitive inhibitor of ACE-2.