RBP4 and metabolic dysfunction-associated steatotic liver disease: Similarly, the expression/secretion of selenoprotein P (SELENOP), fibrinogen-like protein 1 (FGL1/hepassocin) and retinol binding protein 4 (RBP4) impaired insulin signaling and glucose metabolism in both hepatocytes and myotubes, thus contributing to IR and NAFLD development [15,16,17].