PCSK9 and fatty liver disease: Moreover, PCSK9(−/−) mice showed impairment of liver regeneration, while PCSK9(+/−) mice exhibit an improved liver regeneration and resistance to hepatic steatosis (Momtazi-Borojeni et al., 2022); this finding indicates that a moderate level of the PCSK9 protein can protect mice against MAFLD and MASH.