Scientists believe that a protein in (snake) venom helps snakes relocate their prey so they can continue their dinner.

This protein, called a disintegrin, enables the snake to relocate its prey, explains (University of Northern Colorado researcher Anthony) Saviola. He says scientists performed studies where a rattlesnake struck a mouse, and when a second rattlesnake of the same species was given a choice between that mouse or one that had not been injected with venom, the second rattlesnake usually always chose the one with venom.

Snakes also have an advanced olfactory system and special chemosensory organs in their mouths. Snakes will tongue-flick rapidly, says Saviola, to pick up chemical cues in the environment. But it appears to be the disintegrin that helps them find prey.

Integrins, by definition, are a large group of molecules that promote cell adhesion. "Some of these you don't see in normal, healthy tissue," says Saviola, "but you will see them expressed 100 fold in abnormal, cancerous tissue."

The disintegrin protein in snake venom, when injected into cancer cells, binds the outside of the cell via these integrin receptors. Chemotherapy, used most often to help stop the spread of cancer, not only kills cancer cells but also the healthy cells. The disintegrin from snake venom acts differently. "It doesn't kill the cell," says Saviola. "It binds the outside and doesn't allow the cell to communicate with surrounding cells. That's when cancer becomes cancer ... when it spreads throughout the body."