Macrophage MerTK activation is enhanced in nonalcoholic steatohepatitis (NASH) due to suppression of its cleavage by ADAM17, which activates hepatic stellate cells (HSC) via the ERK-TGFβ1 pathway to promote liver fibrosis [46]. Here, TGFB1 is linked to metabolic dysfunction-associated steatohepatitis.