FASN and obesity due to melanocortin 4 receptor deficiency: While it has been shown in previous clinical trials that FASN inhibitors can reduce hepatic de novo lipogenesis and steatosis in patients with obesity and NAFLD [39, 40], it cannot be ruled out that the improvement in steatosis resulting from the suppression of FASN expression by TRIM21 may have also been influenced by fatty acid re-esterification.