In investigating the links of ACE2 /Ang(1–7) and mir-21 in pulmonary fibrosis, we found that the protein levels of ERK/NF-κB, the NLRP3 inflammasome, and collagen were increased, but Spry1 was decreased by over-expression of mir-21, and these effects could not be reversed by ACE2/Ang(1–7) [Fig. 4A,B,C,D]. The gene discussed is NFKB1; the disease is pulmonary fibrosis.