SIRT6 and obesity due to melanocortin 4 receptor deficiency: Regarding ALT and AST levels, no significant difference was observed in the liver between Sirt6 Floxed and LKO mice in the obesity model (Fig. EV5G) but appeared in the DEN-induced HCC model (Fig. EV5D).These data suggest that Sirt6 ablation promoted hepatocellular carcinoma.