Previous clinical trials have shown that Pioglitazone, a PPARγ agonist, can improve hepatic steatosis in NAFLD patients but does not affect NASH or liver fibrosis.38 Our findings suggest that PPARγ may only regulate the transcription of ATGL but not CGI-58, which may explain why Pioglitazone is ineffective in treating NASH and liver fibrosis. This evidence concerns the gene PNPLA2 and fatty liver disease.