TGFBR1 and Hepatic fibrosis: However, similar to global Prom1 deficiency, liver-specific Prom1 deficiency did not change the mRNA levels of Tgfb1 or Tgfbr1. These data indicated that PROM1 deficiency in hepatocytes ameliorated BDL-induced liver fibrosis by depositing ECM in the ductular region.