NRG4 and metabolic dysfunction-associated steatotic liver disease: A study included patients with NAFLD diagnosed by ultrasound also found that circulating Nrg4 levels were negatively associated with NAFLD, where BMI, waist circumference, high-density lipoprotein cholesterol (HDL-C), and homeostatic model assessment for insulin resistance (HOMA-IR) were independently associated with Nrg4 (Tutunchi et al., 2021).