PNPLA2 and fatty liver disease: Acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), 1-O-acylceramide synthase (ACS), 1-acyl-sn-glycerol-3-phosphate acyltransferase β (AGPAT2) and adipose triglyceride lipase (ATGL) have been reported to be crucial to TG metabolism in vitro and liver steatosis in vivo [18].