Some studies demonstrated that NAFLD patients had significantly increased RBP4 levels compared with healthy control individuals [14, 15], whereas other studies found no association between RBP4 levels and NAFLD [16, 17], Furthermore, some groups reported decreased circulating levels of RBP4 in patients with NAFLD [18, 19], Given the inconsistent reports, a systematic review and meta-analysis on this subject is warranted. The gene discussed is RBP4; the disease is metabolic dysfunction-associated steatotic liver disease.