TLR4 and Hepatic fibrosis: Likewise, using a CCL4-induced liver fibrosis animal model, Ohara et al. proved that EVs from amnion-derived MSCs (AMSC-EVs) could significantly reduce the number of Kupffer cells (KCs), mRNA expression of inflammatory factors, activation of hepatic stellate cells (HSC), and the lipopolysaccharide (LPS)/toll-like receptor 4 (TLR4) signaling pathway, thereby reducing inflammation and fibrosis [127].