Despite the existence of reductive carboxylation glutaminolysis in hepatocellular carcinoma HepG2 cells, the HepG2 cell metabolism represents a prototype of predominating OXPHOS glutaminolysis, employing glutaminase followed by the cytosolic ALT1 or matrix ALT2 reaction, both producing 2OG. Here, GPT2 is linked to hepatocellular carcinoma.