Herein, our results showed that ATGL protein levels were decreased in the liver tissues of high-fat diet (HFD)-fed mice, naturally obese mice, and cholangioma/hepatic carcinoma patients with hepatic steatosis, as well as in the oleic acid-induced hepatic steatosis cell model, while ATGL mRNA levels were not changed. Here, PNPLA2 is linked to fatty liver disease.