CCL4 and Hepatic fibrosis: It has been reported that a large number of Ly-6Chi subgroup macrophages can infiltrate into the liver and exert pro-inflammatory and pro-fibrotic functions during the progression stage of carbon tetrachloride (CCL4)-induced liver fibrosis, and Ly-6Chi subgroup macrophages can transform into Ly-6Clo subgroup macrophages after CCL4 removal, leading to collagen degradation and gradual liver repair (26).