The data in zebrafish, together with the known lower expression of estradiol receptor in the liver of individuals with NASH (Erkan et al., 2013) and the inhibitory effect of estradiol on expression of TGFB1, TNFA (Itagaki et al., 2005; Yasuda et al., 1999), IL6 and IL1B (Kireev et al., 2010; Rogers and Eastell, 2001) also suggest a protective effect of fertile status on the severity of liver damage in NAFLD. This evidence concerns the gene ESR1 and metabolic dysfunction-associated steatohepatitis.