Feng et al. (Feng et al., 2019) found that Tan IIA reduces the levels of tumor necrosis factor-α (TNF-α), IL-6, and IL-1β, inhibits the expression of type I collagen, FN, and α-SMA, and decreases the expression levels of TGF-β1, p-Smad2/3, and p-Smad3 while up-regulating the expression of Smad7 in the lung tissue of a rat model of silica-induced pulmonary fibrosis. Here, SMAD2 is linked to pulmonary fibrosis.