SMAD3 and Hepatic fibrosis: In this study, we investigated the effects of exosomes of WJ-MSCs on genes that are involved in liver fibrosis progression, including TGF-β, α- smooth muscle actin (α-SMA), collagen1α genes in the presence or absence of cholesterol in the LX2 cell line (a type of cell derived from HSCs), and also phosphorylation of Smad3 protein level.