FASN and fatty liver disease: Numerous studies have demonstrated that rapamycin alleviates hepatic steatosis via inhibiting some important lipid metabolic enzymes including sterol regulatory element binding protein 1c (SREBP1c), SREBP2, fatty acid synthase (Fasn), acetyl-CoA carboxylase (ACC), stearoyl-CoA desaturase-1 (SCD1), and low-density lipoprotein receptor (LDLr), as described by our group [40] and others [41], [42].