Figure 1. Summary scheme of MerTK-mediated macrophage HSC crosstalk pathway in fibrotic NASH. In healthy liver, MerTK in resident macrophages is inactivated due to the absence of GAS6. In steatosis, ATRA-induced MerTK cleavage suppresses MerTK signaling. However, during progression to fibrotic NASH, MerTK signaling is restored by suppression of MerTK cleavage, leading to TGFB1 induction and HSC activation.