FAS and metabolic dysfunction-associated steatotic liver disease: To screen the PCSK9 downstream factors involved in the effects of metformin on olanzapine-induced NAFLD, we determined the expression of a series of hepatic lipid metabolism-associated genes, including ACC, FAS, SCD1, DGAT1, DGAT2, CPT1α, SCAD, PPARα, and ACOX1.