Thus, to further determine whether latent TGF-β1 activated by ROS is involved in pulmonary fibrosis in vitro, we treated A549 cells in the presence of TGF-β receptor-specific inhibitors SB431542 and found that blocking TβR inhibited collagen I deposition in A549 cells co-treated with latent TGF-β1 and high glucose. Here, TGFB1 is linked to pulmonary fibrosis.