SMAD3 and pulmonary fibrosis: For instance, artemisinin has been found to inhibit myofibroblast growth and reduce bleomycin-induced pulmonary fibrosis by downregulating pro-fibrotic proteins such as TGF-β1, Smad3, HSP47, α-SMA, and collagen type I (Wang et al., 2015; Yang et al., 2015).