As compared to non-EV-treated animals, the hUC MSC EV treatment of animals on either of the injurious diets consistently resulted in restored serum AST and ALT levels, reduced steatosis, the reversal of lipid-related gene expression (SREBP-1c, PPAR-α, Fabp5, CPT1α, ACOX, FAS), and a reduced frequency of F4/80 macrophages in the liver, while also causing the macrophages to de-polarize, favoring a reduced CD11+ M1 pro-inflammatory phenotype and an increased CD206+ M2 anti-inflammatory phenotype [130]. The gene discussed is PPARA; the disease is steatosis.