SMAD2 and silicosis: Moreover, expression of TGF-β1, Smad2, and Smad3 was downregulated, and Smad7 expression was upregulated.<h4>Conclusion</h4>These findings suggest that the anti-fibrotic effect of CoQ10 on silicosis may be associated with reducing pulmonary inflammation and oxidative stress, thereby inhibiting the TGF-β1/Smad signaling pathway.