Similarly, an in vivo study found that MSC transplantation reduced the levels of TGF-β released by Kupffer cells and M2 macrophages in a rat model of hepatic fibrosis and decreased the expression of α-smooth muscle actin (α-SMA) and the number of collagen fibers in hepatocytes [67]. The gene discussed is TGFB1; the disease is Hepatic fibrosis.