PTGS2 and metabolic dysfunction-associated steatotic liver disease: In male ApoE knockout C57BL/6J mice, the simultaneous administration of super-low doses of LPS with administration of an HFD resulted in the development of nonalcoholic fatty liver disease (NAFLD) steatohepatitis, followed by intense leukocyte infiltration and sustained expression of p38 mitogen-activated protein kinase (MAPK) [52], a molecule involved in the production of inflammatory mediators such as TNF-α and cyclo-oxygenase 2 (COX-2).