Serum Biomarkers: Several serum biomarkers, including markers of lipid metabolism (e.g., adiponectin, leptin), liver injury (e.g., AST to ALT ratio, cytokeratin-18 fragments), and inflammation (e.g., C-reactive protein), have been investigated as potential predictors of hepatic steatosis progression [49]. The gene discussed is LEP; the disease is fatty liver disease.