By example, Stättermayer et al. have highlighted evident differences in copper liver concentration between NAFLD patients who have the Patatin-like phospholipase domain-containing protein 3 (PNPLA3) mutation associated with presence of NASH and hepatic fibrosis without MetS respect to patients with MetS. This evidence concerns the gene PNPLA3 and metabolic dysfunction-associated steatohepatitis.