In contrast, Jiang et al. [32] have studied levels of irisin in liver tissues of NAFLD patients, and their results showed that the irisin levels in NAFLD patients were higher than those in healthy people (66.8 ± 0.45 vs. 42.69 ± 1.00 ng/ml, respectively; P < 0.01). The gene discussed is FNDC5; the disease is metabolic dysfunction-associated steatotic liver disease.