In acute liver injury (ALI) induced by CCl4, MSC-Exos from mouse compact bones causes system XC− activation to block CCl 4-induced iron death in hepatocytes by down-regulating mRNA levels of prostaglandin endoperoxide synthase 2 (Ptgs2) and lipoxygenases (LOXs) and by concomitant restoration of protein levels of SLC7A11 in primary hepatocytes and mouse liver [103]. The gene discussed is PTGS2; the disease is medical procedure.