ASS1 and hepatocellular carcinoma: The silencing of argininosuccinate synthetase 1 (ASS1) is a common occurrence in many solid and liquid tumors, as many sarcomas, melanomas, bladder cancers, prostate cancers, small cell lung cancers (SCLC), hepatocellular carcinomas, and leukemias are deficient in this enzyme (1–7).