PPARG and fatty liver disease: However, in methionine-choline deficient diet-induced models of NAFLD, overexpression of PPARγ or treatment with PPARγ agonists, including rosiglitazone and pioglitazone, has been shown to improve hepatic steatosis and liver lesions [18–21], whereas heterozygous deficiency in PPARγ or administration of PPARγ antagonists led to an increase in steatosis and lesions [19].