Oncogenes are genes that cause cancer.

The first 200 words of this essay...

Oncogenes are genes that cause cancer. They were first found in viruses, but their evolutionary history implies that normal vertebrate cells have genes whose abnormal expression can lead to cancerous growth, as this article from Scientific American explains.

Oncogenes

Can the cancer cell be understood? Since no one can yet explain how a normal cell controls its growth, it may seem foolhardy to think the abnormal rules governing the growth of a cancer cell can be deciphered. Yet the history of biology records many instances in which the study of abnormalities has illuminated normal life processes. Recent developments in cancer research have added a dramatic new example. For the first time investigators have perceived the dim outline of events that can induce cancerous growth. Enzymes that catalyze those events have been identified, and so have the genes specifying the structure of the enzymes.

These advances have come from the study of viruses that induce tumors. Recent years have seen an enthusiastic search for viruses that cause cancer in human beings. The search has been largely unsuccessful, leading many informed observers to doubt that viruses will ever prove to be a major cause of human cancer. Some