Hepatocellular carcinoma cells cultured in normoxia synthesized acetyl-CoA that was shuttled to mitochondria for use as an essential energy source, while during hypoxia ACSS2 expression increased nearly five-fold [63], enhancing the rate of acetate utilization and the resultant acetyl-CoA synthesized was used to increase fatty acid synthesis and the acetylation of histone H3K9, H3K27, and H3K56 [64]. This evidence concerns the gene ACSS2 and hepatocellular carcinoma.