COL1A1 and Hepatic fibrosis: However, this different anti-fibrosis efficacy between Gly-β-MCA and UDCA was not reflected at the hepatic fibrosis gene expression level, with the induction of hepatic collagen, type I, α1 (COL1A1) and tissue inhibitor of metalloproteinase 1 (TIMP1) mRNA fully normalized to the level of WT mice (Fig 3D, E), which was consistent with reduced liver fibrosis in the treated mice (Fig. 3C).