GPT and fatty liver disease: Nmnat1-LKO per se was not sufficient to induce, but it aggravated alcohol-induced hepatic steatosis and liver injury based on the measurements of ALT and AST levels in the plasma, liver TG level, hematoxylin and eosin (H&E) and Oil red O staining, liver weight, and liver weight–to–body weight ratio (Fig. 3, F to J, and figs.