Chronic unresolved inflammation contributes to the development of nonalcoholic steatohepatitis (NASH), a disorder characterized by lipotoxicity, fibrosis, and progressive liver dysfunction.In this issue of the JCI, Han et al. report that maresin 1 (MaR1), a proresolving lipid mediator, mitigates NASH by reprograming macrophages to an antiinflammatory phenotype.
MaR1 effects on fatty liver disease were tested in ob/ob (2-10 μg kg<sup>-1</sup> i.p., 20 days) and in diet-induced obese (DIO) mice (2 μg kg<sup>-1</sup>, i.p., or 50 μg kg<sup>-1</sup>, oral gavage for 10 days), as well as in cultured hepatocytes.