Due to the repressive effect of FXR activation on BA synthesis, the agonist of FXR could decrease the abnormally high levels of hepatic BAs in cholestatic liver diseases (Hirschfield et al., 2015), which contributed to the approval of obeticholic acid in the treatment of PSC by the FDA (Markham and Keam, 2016). The gene discussed is NR1H4; the disease is Cholestatic liver disease.