ARG1 and metabolic dysfunction-associated steatohepatitis: In addition, we found that treatment with IL-33 reduced protein expression of IL-12p70 (M1 marker, Figure 5g) and mRNA expression of TLR2 (M1 marker, Figure 5l), and enhanced mRNA expression of Arg-1 and CD206 (M2 markers, Figure 5i, 5j), indicating that IL-33 treatment promoted hepatic M2 macrophage activation in experimental NASH.