Background and Aim
Arginine is a nonessential amino acid for humans and mice because it can be synthesized from citrulline by argininosuccinate synthetase (ASS) and argininosuccinate lyase. Hepatocellular carcinoma (HCC) is believed to be auxotrophic for arginine through the lack of expression of ASS. However, there are also some ASS-positive HCC cells. Therefore, the aim of this article was to study the levels of arginine and the expression of ASS in patients with HCC.