French and American scientists said Wednesday they have identified a “Jekyll and Hyde” type of cancer gene that could lead to better ways to diagnose and treat the disease.

Unlike other cancer genes that either promote cancerous tumors or block their growth, researchers at the University of Lyon in France and the Buck Institute in Novato, California have found a gene that does both.

The gene called DCC is a receptor on the surface of cells. It was thought to be a suppressor gene that stops cancerous growth but the researchers discovered that it could be switched to promote cancer by a protein.

“This new line of research holds promise for potential therapies or predictive tests for cancer,” said Dale Bredesen, president of the Buck Institute and a co-author of the research published in the science journal Nature.

DCC usually acts as a brake and stops cancerous cells from proliferating and causes them to commit suicide. But when the growth factor protein called netrin-1 is abundant the brake is removed.

In a study of mice genetically engineered to produce high amount of netrin-1, the scientists found the animals had a high rate of precancerous growths. But when they combined it with a genetic mutation that causes benign tumors, the mice developed colorectal cancer.

“Detecting abnormalities in levels of netrin-1, or other similar molecules, might help us identify those patients at risk of developing malignancies; furthermore, by manipulating the abundance of netrin-1, we might be able to stop the cancer in its tracks,” said Bredesen.

Although the mouse study involved colorectal cancer, Bredesen and his French colleagues said the finding could be applicable to other types of cancer.

“This interaction described between a particular receptor and growth factor in digestive tumors is probably true for other pairs of receptors and growth factors and for other types of tumors,” Patrick Mehlen, of the University Claude Bernard Lyon 1 in France, said in a statement.

“This observation should lead researchers to look at cancer development from a completely different angle,” he added.

The scientists believe DCC could be the first of a number of conditional tumor suppressors.