Signalling via the constitutive androstane receptor (CAR;NR1I3) and pregnane X receptor (PXR;NR1I2) are major mechanisms for cellular response to exposure to xenobiotics and endogenous molecules. CAR plays an important role orchestrating the metabolism and detoxification of potentially toxic chemicals, by upregulating genes that are involved in the clearance of both xenobiotics and endobiotics. Although CAR-mediated metabolism of drugs (e.g., acetaminophen) can lead to the production of toxic metabolites, induction of CAR regulated genes has emerged as a therapeutic strategy for the treatment of various diseases.