Consistent with the results in HepG2 cells, the expression of PPARγ2 and its steatosis target genes CD36, FABP4, PLIN2, and CIDEC2 was enhanced in the livers of Ad-JMJD2B-injected mice compared with those in the livers of Ad-GFP-injected mice; therefore, our in vivo data also showed that JMJD2B is an epigenetic regulator in the development of hepatic steatosis. This evidence concerns the gene FABP4 and fatty liver disease.