 Over the last decade, a new theory of cancer biology has emerged. The cancer stem cell. Normal stem cells are involved in organ repair. Stained here in red, they travel around the body, sit and wait until there's some damage, and step in and replace whatever structures are necessary. Lost the little skin here, bone or muscle there need to regrow a new tooth? These cells are ready and willing. And the best part, they're built to last a lifetime. But those same qualities—migration, colonization, proliferation, self-renewal, immortality— can be used against us when stem cells go bad and decide to build tumors instead. Cancer stem cells may explain cancer spread and cancer recurrence. That may be why cancer tends to come back. There may be no cure, only remission. You can have a breast cancer relapse 20 to 25 years after you thought it went away, thanks potentially to cancer stem cells. Our current armamentarium of chemo, drugs, and radiation is based on animal models. If the tumor shrinks, it's a success. But lab rats only live two or three years. All these new fancy therapies like anti-angiogenesis, cutting off the blood supplies to tumors, that's great. But the cancer stem cells may be like, fine, I'll go somewhere else and grow another tumor. What we need is to strike at the root of cancer. Treatments aimed not at just reducing tumor bulk, but rather at targeting the quote-unquote beating heart of the tumor, the cancer stem cell. Enter broccoli. A dietary component of broccoli and broccoli sprouts appears to inhibit breast cancer stem cells. Breast tissue naturally has lots of stem cells, right? Your body never knows when you're going to get pregnant and have to start making a lot of new milk glands. Researchers recently discovered this compound in broccoli that may destroy cancerous stem cells and keep them from going rogue in the first place. Here's an estrogen receptor-positive human breast tumor. Here's an estrogen receptor-negative breast tumor. Let's add some broccoli juice. Going, going, nearly gone. Stem cell hotspots before and after the broccoli.