FGF21 and metabolic dysfunction-associated steatotic liver disease: To better delineate the systemic consequences of this NAFLD in lean mice in a sex-dependent manner, we performed ELISA assays for circulating hepatokines, namely, Fibroblast Growth Factor 21 (FGF21), Retinol Binding Protein 4 (RBP4), and Fetuin A also referred to as alpha2-HS-glycoprotein.