LXRA is a tissue-specific cofactor that permits RXRA to function as a potent 9cRA receptor with a distinct target gene specificity. It specifically interacts with RXRA in vivo to form a functional heterodimer in which RXRA is the ligand-binding subunit. Additionally, LXR activity is critical for physiologic lipid metabolism and transport. LXRs are endogenous inhibitors of atherogenesis and are targets for therapeutic intervention in cardiovascular disease. Furthermore, LXRs and their ligands are negative regulators of macrophage inflammatory gene expression. LXR is also found that as a transcriptional switch that integrates hepatic glucose metabolism and fatty acid synthesis. The LXR-IDOL-LDLR axis defines a complementary pathway to sterol response element-binding proteins for sterol regulation of cholesterol uptake.