However, the Yale team found that these mutations did not have to co-exist in the same cell to cause tumors. A cell with only mutant RAS can develop into a malignant tumor if helped by a nearby cell with defective scribble. They also found stress conditions such as a wound could trigger cancer formation. For instance, RAS cells developed into tumors when a wound was induced in the tissue. The culprit underlying both phenomena turned out to be a signaling process called JNK, which is activated by environmental stress conditions.

"A lot of different conditions can trigger stress signaling: physical stress, emotional stress, infections, inflammation - all these things. Another bad news for cancer" Xu said.

While the paper shows it is easier than previously thought for cancer to take root in the body, it also identifies new targets to prevent and treat one of the deadliest diseases in the developed world. The Yale team found that the JNK stress signaling travels from one cell to the next, but that the propagation can be blocked.

"Better understanding of the underlying mechanism causing cancer always offers new tools to battle the disease," Xu said.