Oncogene

n. (Medical) mutated gene that may result in the onset of cancer in an animal or human

An oncogene is a modified gene, or a set of nucleotides that codes for a protein and is believed to cause cancer. Genetic mutations resulting in the activation of oncogenes increase the chance that a normal cell will develop into a tumor cell. Since the 1970s, dozens of oncogenes have been identified in human cancer. Oncogenes are figuratively thought to be in a perpetual tug-of-war with tumor suppressor genes which act to prevent DNA damage and keep the cell's activities under control. There is much evidence to support the notion that loss of tumor suppressors or gain of oncogenes can lead to cancer.
See more at Wikipedia.org...

On·co·gene n. A gene that causes the transformation of normal cells into cancerous tumor cells, especially a viral gene that transforms a host cell [more]Oncogene - Community and Resources

Noun
1. a gene that causes normal cells to change into cancerous tumor cells
(synonym) transforming gene
(hypernym) gene, cistron, factor

adj. oncogenic