Genetic models of NAFLD include db/db mice, homozygous for a mutation in the leptin receptor leading to defective leptin signaling, ob/ob mice with autosomal recessive mutation in the leptin gene leading to mice that are grossly overweight, hyperphagic, hyperinsulinemic, hyperglycemic, and resistant to insulin. The gene discussed is LEP; the disease is metabolic dysfunction-associated steatotic liver disease.