COL1A1 and Hepatic fibrosis: The conversion of Ly6Chi to Ly6Clo macrophages significantly downregulated the expression levels of Ly6Chi macrophage-derived PDGF, TNF-α, and IL-1β in the fibrotic liver, which was accompanied with the reduced expression of HSC-derived α-SMA and Col1α1 and the reduction of liver fibrosis.