For example, overexpression of diacylglycerol acyltransferase 2 (DGAT2) which catalyzes the final step in triacylglycerol (TG) biosynthesis in the liver increases hepatic steatosis, manifested as increased amounts of hepatic TG, diacylglycerol, ceramides, and unsaturated long-chain fatty acyl-CoAs. The gene discussed is DGAT2; the disease is fatty liver disease.