Recombinant human transforming growth factor(TGF)β3 is an important cytokine for formation of healthy skin and healing response of embryos without scarring. In actively growing hypertrophic scar fibroblasts, the expression of TGFβ2 increases and TGFβ3 is low. However, in embryonic scar-free healing, TGFβ3 is high. When TGFβ1, TGFβ2, and TGFβ3 combine with the same receptor complex on the cell surface, TGFβ3 induces the receptor to compete with TGFβ1 and TGFβ2 to reduce their expression and inhibit the formation of scars. In the late period of wound healing, TGFβ3 reduces scar size to reverse the effects of TGFβ1 and TGFβ2 by decreasing the aggregates of inflammatory cells and the deposition of connective tissue, ensuring wound healing and preventing excessive scarring. Preclinical safety and toxicology studies suggest that the TGF β family of proteins accumulate mainly in the liver(~60%) and in other tissues, including the kidneys(~20%) and the blood(~10%). In addition, the TGFβ family of proteins minimally(
