The bile acid receptor FXR (Farnesoid X Receptor) is a member of the nuclear receptor family, primarily composed of two subtypes, FXRα and FXRβ. FXR is highly expressed in the liver, intestines, kidneys, and adipose tissue, serving as a key regulator of bile acid, lipid, and glucose metabolism. It regulates bile acid synthesis, secretion, and circulation by sensing bile acid concentrations, while also impacting cholesterol, triglyceride, and blood glucose levels. FXR activation participates in inhibiting cholesterol 7α-hydroxylase (CYP7A1), reducing bile acid synthesis. Specific gene expression patterns and mutations are associated with diseases such as liver disorders, cholelithiasis, and metabolic syndrome.