While acetyl-CoA acetyltransferase 1 (ACAT1), a mitochondrial enzyme that acetylates GNPAT at the K128 site, promotes lipid metabolism and hepatocarcinogenesis by stabilizing fatty acid synthase (FASN) metabolism and hepatocarcinogenesis, SIRT4 deacetylates glycerol O-acyltransferase (GNPAT) and decreases its expression in HCC 200. The gene discussed is GNPAT; the disease is hepatocellular carcinoma.