TGFB1 and systemic sclerosis: We also have demonstrated that the sera containing WYHZTL reduces the expression levels of collagen I/III through regulating some key signal molecules, such as TGF-β1 receptor I, p-Smad2/3, Smad7, in TGFβ1/Smad Signaling pathway of skin fibroblasts obtained from SSc patients [10].