Oncomodulin--a widely distributed, tumour-specific, calcium-binding protein.

The seemingly de novo appearance of oncomodulin and increased levels of calmodulin were observed (using specific radioimmunoassays) in several types of mouse, rat and human tumours. Oncomodulin could not be found in any normal (adult or fetal) rodent or human tissue. Tryptic peptide mapping showed that oncomodulin in rat and mouse tumours was identical, and was not a fragment of either calmodulin or troponin C. A possible role for oncomodulin in the deregulated cell proliferation of cancer cells was suggested by its ability to stimulate DNA synthesis in isolated rat liver cells.