Therefore, we hypothesized that ACE2/Ang(1–7) prevents AngII-induced pulmonary fibrosis by inhibiting the expression of mir-21, and that mir-21 mediates the inhibitory effect of ACE2/Ang(1–7) on AngII-induced-NLRP3 inflammasome activation via the ERK/NF-κB pathway by targeting Spry1 in lung fibroblasts. This evidence concerns the gene ACE2 and pulmonary fibrosis.