The retinoid X receptors (RXRs) are nuclear receptors that mediate the biological effects of retinoids by their involvement in retinoic acid-mediated gene activation. RXRα is the dimerization partner for the type II nuclear receptors that includes the liver X receptor (LXR). The LXR receptor is activated by oxysterol ligands and forms a heterodimer with RXR. After heterodimerization LXR initiates transcription of target genes by binding to the LXR response element. LXR/RXR is involved in the regulation of lipid metabolism, inflammation, and cholesterol to bile acid catabolism...