NRG4 and metabolic dysfunction-associated steatotic liver disease: Serum NRG4 concentrations are inversely associated with non-alcoholic fatty liver disease, metabolic syndrome and cardiovascular disease in obese humans, while elevated NRG4 is associated with a decreased risk of NAFLD in both children and adults (Cai et al., 2016; Jiang et al., 2016; Wang et al., 2019).