The peroxisome proliferatoractivated receptors (PPARs) which respond to fatty acids, liver X-activated Receptor (LXR) which respond to oxysterols and glucose, and farnesoid X Receptor (FXR) which respond to bile acids are ligand-activated transcription factors and are involved in the regulation of lipid metabolism (Goldwasser et al., 2010; Guo et al., 2006).