FGF21 and metabolic dysfunction-associated steatotic liver disease: Many proteins have been confirmed as biomarkers in non-alcohol fatty liver disease (NAFLD) of human beings, such as fibroblast growth factor-21 (FGF-21), adiponectin (ADP), Lipoprotein-associated phospholipase A2 (LP-PLA2), hemoglobin (Hb)8–10.