LEP and metabolic dysfunction-associated steatotic liver disease: Leptin stimulated IFN-γ production in circulating CD4+ cells from control subjects and patients with NAFLD; however, we observed higher fold of increase indexes in patients with NAFLD than in control subjects [1.26 (1.17–1.40) vs. 1.06 (1.04–1.35), respectively; p = 0.011] (Fig 4A).