TGFB1 and fibrosis: Since TGF-β1 is important in the development of sub-epithelial fibrosis, we determined the effect of BAIC on the levels and expression of TGF-β1. As shown in Fig. 2C, the OVA/OVA/VEH mice showed a significant expression of TGF-β1 especially in the subepithelial mesenchymal regions and increased levels in lung cytosol relative to the SHAM/PBS/VEH mice (Fig. 2C, iv).