Compared with their Sham controls, VSG failed to decrease the liver weight (Fig. 4C), hepatic steatosis (Fig. 4D and 4E), ALT (Fig. 4F), and AST (Fig. 4G) in TREM2 KO mice, suggesting that TREM2 is required for the VSG-induced reversal of MASH. This evidence concerns the gene TREM2 and steatosis.