Carolyn Bertozzi studies sialic acid, a sugar that seems to deceivthimmunsystem, allowing cancer cells to evadthbody’s defenses. (American Chemical Society)

Your cells are coated with sugar, and when it comes to cancer, that's anything but sweet. In a recent talk at TEDx Stanford, chemical biologist Carolyn Bertozzi explains why.

Bertozzi's work focuses on the complex, sugary structures surrounding your cells. That foliage-like coating, it turns out, can tell scientists a lot about your body — it even reveals your blood type.

But the stories the sugars tell your body's defenses can be forbidding.

Ideally, the immune system can figure out which cells are bad, attack them and protect the body from disease. In the case of cancer cells, though, a special sugary coating tricks the immune system into ignoring them.

Bertozzi studies sialic acid, a sugar that's denser in cancer cells than in other cells. It seems to deceive the immune system, allowing the cancer cells to evade the body's defenses. Unnoticed and unchallenged, cancer cells are free to divide and run wild inside the body.

The news isn't all bad. In her talk, Bertozzi explains researchers' plans to use drugs to strip the sugars away from cancer cells. Once these cells' sour secret is exposed, they hope, the immune system will be able to devour them before they have a chance to take hold.

It's exhilarating stuff. Bertozzi's 6½ -minute talk may leave you wondering what else your cells' coatings might be able to do — and how those revelations might change the way we fight cancer.