SMAD3 and systemic sclerosis: Our studies preliminarily demonstrated that Yiqihuoxue treatment for SSc significantly reduced collagen production in both in vivo bleomycin-induced mouse models and in vitro SSc dermal firbroblasts and TGF-β1-induced NIH/3T3 fibroblasts, via down-regulating the phosphorylation of Smad3 and the activity of SBE in the type I collagen promoter.