GPT and hepatocellular carcinoma: It was proven previously that treatment of rat hepatocellular carcinoma with β-carotene inhibited significantly tumor growth, enhanced NK cells infiltration as well as production of IL-2 and TNF-α, resulting in an improved clinical outcomes as attested by significant decrease of blood alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities [50].