GPT and metabolic dysfunction-associated steatohepatitis: Although the difference in body weight between Gdf15−/− and control mice was less pronounced after AMLN diet feeding for 12 weeks compared to feeding for 30 weeks (Fig. 4c), Gdf15−/− mice had significantly higher liver weight adjusted for body mass and serum ALT/AST levels after 12 weeks of AMLN diet feeding (Supplementary Fig. 4i,j), suggesting that GDF15 acts as an inhibitory factor against liver hypertrophy and could play a protective role against NASH regardless of body weight changes.