METTL3 and non-alcoholic fatty liver: However, after they were fed an HFD for 12 weeks, Mettl3-HKO mice displayed more severe NAFL, as revealed by higher serum ALT activities (Fig. 2d), higher liver weights (Fig. 2e, f), more hepatic lipid droplets (Fig. 2f), and higher liver TAG levels (Fig. 2g) compared with Mettl3flox/flox mice.