Wang et al. [20] suggested that vitamin A derivatives such as retinoic acid inhibited liver fibrosis induced by BDL by reducing the expression of transforming growth factor-β1, connective tissue growth factor, and tissue inhibitors of metalloproteinase-1, diminishing the inhibition of tissue inhibitors of metalloproteinase-1 on matrix metalloproteinase-2 and matrix metalloproteinase-13 then promoting the activity of matrix metalloproteinase-2 and matrix metalloproteinase-13. The gene discussed is MMP2; the disease is Hepatic fibrosis.