GRN and Hepatic fibrosis: Importantly, hepatic macrophages mediate the transdifferentiation of hepatic stellate cells (HSCs) into collagen-producing myofibroblasts by secreting several profibrotic factors, such as transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF), and granulin (GRN) in liver fibrosis [1, 5, 7–9].