Lipoproteins are composed of lipids, cholesterol and apolipoproteins, and the expression of apolipoproteins A1, A4 and C3 (APOA1, APOA4 and APOC3) increased significantly in the hepatic steatosis groups (Fig. 4H), suggesting an increased level of cholesterol transport. The gene discussed is APOA1; the disease is fatty liver disease.