The maintenance of BAs homeostasis is regulated by the farnesoid X receptor (FXR) via transcriptional repression of key enzymes involved in BAs synthesis, such as cholesterol 7α­hydroxylase (CYP7A1) and sterol 12α‐hydroxylase (CYP8B1).[6]SLC27A5 mRNA expression was upregulated after FXR agonist GW4064 treatment.[35] However, the underlying mechanisms of SLC27A5 downregulation in liver fibrosis remain unclear. The gene discussed is CYP8B1; the disease is Hepatic fibrosis.