Description of the predicted marker genes

The 11 liver marker genes that we identified and validated with RT-PCR are AKR1D1, FGG, APOA2, CYP2C8, GC, CPS1, CYP2E1, APOC3, SERPINC1, AHSG, and AMBP. We confirmed by PCR the liver-specific expression of CYP2C8, GC, CPS1, CYP2E1, APOC3, SERPINC1, AHSG, and AMBP. AMBP gene encodes the two plasma glycoproteins alpha-1-Microglobulin (A1M) and bikunin. A1M belongs to the superfamily of lipocalin transport proteins and may play a role in the regulation of inflammatory processes, whereas bikunin is an urinary trypsin inhibitor. The strict liver-specific transcription of the AMBP gene appears to be due to the presence of a strong liver-specific enhancer [1]. AHSG is synthesized by hepatocytes and secreted into serum. It is involved in insulin resistance and fat accumulation in the liver [2]. CYP2C8 and CYP2E1 encode members of the cytochrome P450 superfamily of enzymes. Cytochrome P450 epoxygenases are predominantly expressed in the liver [3] and they catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. GC encodes a protein that belongs to the albumin gene family. It functions predominantly as a transporter protein for vitamin D and its metabolites [4]. APOC3 is a very low density lipoprotein (VLDL) protein. APOC3 inhibits lipoprotein lipase and lipoprotein remnant uptake by the liver [5, 6]. SERPINC1 is a plasma protease inhibitor, synthesized in the liver and a member of the serpin superfamily. It is the principal plasma serpin of blood coagulation proteases and functions as inhibitor of thrombin and other factors by the formation of covalently linked complexes.