Next, we tested the plasma levels of cytokines and adipokines in NAFLD and non-NAFLD monkeys, and found that TNF-α, IL-1β, IL-2 and IL-6 were no differences between the groups of USS0–1 and USS2–3 (Fig. 5a–d), and no correlation was observed between these cytokines with the USS. Here, IL6 is linked to metabolic dysfunction-associated steatotic liver disease.