Tumor markers can facilitate understanding molecular cell biology of neoplasia and provide potential targets for the diagnosis and insight for intervention. We here identify a novel murine gene, hepcarcin (hcn), encoding a 7-kb mRNA-like transcript. The gene appears to be the murine ortholog of the human alpha gene, that is, MALAT-1. The gene and homologs lack credible open reading frames, consistent with a highly conserved large noncoding RNA (ncRNA). In all nodules of procarcinogen-induced murine hepatocellular carcinomas (HCCs) and human HCCs, expression was markedly elevated compared to the uninvolved liver. Quantitative analyses indicated a 6-7-fold increased RNA level in HCCs versus uninvolved liver, advancing this as a molecule of interest. This ncRNA was overexpressed in all five non-hepatic human carcinomas analysed, consistent with a potential marker for neoplastic cells and potential participant in the molecular cell biology of neoplasia.