RBP4 and metabolic dysfunction-associated steatotic liver disease: In contrast, some researches demonstrated that serum RBP4 is not a predictive factor in NAFLD [22], and RBP4 did not differ among NAFLD histological groups and thus did not identify non-alcoholic steatohepatitis (NASH), the advanced stage of NAFLD [23], another study showed that in NAFLD patients, serum RBP4 was significantly lower as compared with controls and did not correlate with insulin resistance [24].