Mesenchymal stromal cells (MSCs) are a promising drug for the treatment of liver diseases, as they restore liver function and reverse fibrosis in various models of liver injury[1]. MSCs act as "healing signaling cells" that reshape the pathological environment of the liver through four mechanisms: immunomodulation, direct action against fibrosis, promotion of regeneration, and metabolic regulation[1]. The key mechanism is the inhibition of the activation of hepatic stellate cells and the polarization of macrophages from the pro-inflammatory type M1 to the anti-inflammatory type M2[1]. Clinical trials have shown that infusion of allogeneic MSCs is safe and effective, reducing MELD scores and increasing albumin levels in patients with acute-chronic liver failure[2]. MSC treatment also significantly reduced INR and ALT levels without increased incidence of adverse effects[2]. In patients with hepatitis B associated with acute liver failure, MSC transplantation was safe and effective and improved patient survival[1].