FIGURE 3: Lipid metabolism is crucial for liver regeneration. Fatty liver has an altered metabolism in lipids that affects its ability to regenerate after various injuries. Lipid accumulation during liver regeneration induces a transient steatosis with transient ER stress that is functional to proper proliferation of hepatocytes. On the contrary, the chronic steatosis and ER stress in fatty liver result in an altered lipid asset that could be addressed as the origin of the failure of regeneration. SIRT1, as a major player in lipid metabolism control, through its deacetylase activity on H3-histone at gene promoters, controls the activation of various UPR genes such as XPB1, CHOP and ATF4.