10 μmol/L Tanshinone IIA can reduce the expression of transforming growth factor-β1 (TGF-β1) receptor and the effect is significant.[37] Experiments have shown that[38] Tanshinone IIA can inhibit the signaling pathway of TGF-β1 and the key factor Smad2/3 in rats with pulmonary fibrosis. This evidence concerns the gene SMAD2 and pulmonary fibrosis.