Genetic models have been created to either mimic a human polymorphism implicated in NAFLD occurrence [such as the patatin-like phospholipase domain-containing 3 (PNPLA3) polymorphic mice], to recapitulate characteristics of the human metabolic syndrome better than diet induction (such as leptin- or leptin receptor-deficient mice), to better depict or to more rapidly proceed to a particular stage of the NAFLD spectrum. The gene discussed is PNPLA3; the disease is metabolic syndrome.