Regulation of gene expression in the liver is of particular interest given its vital roles in maintaining homeostasis and health, including synthesis of most essential serum proteins, the production of bile and its carriers, and the regulation of nutrients. The liver is also the predominant organ in xenobiotic metabolism, and it has been estimated that 75% of the 200 most widely prescribed drugs are eliminated from the body through liver metabolism [11]. Altered metabolism by genetic factors affects the systemic availability and residence time of xenobiotics and hence their toxic and pharmacologic effects [12].
