A xenobiotic-sensing receptor is a receptor that binds xenobiotics. They include the following nuclear receptors: * Constitutive androstane receptor (CAR) * Pregnane X receptor (PXR) CAR and PXR are xenobiotic receptors and they both are members of NR1I nuclear receptor family. The regulate the metabolic pathway for the elimination of cholesterol. However, there is no physiological ligands was identified. Xenobiotic receptors recognize the foreign chemicals and trigger detoxification and metabolism pathways in different host tissues.