""I think the cancer–stem-cell hypothesis will apply to every kind of cancer," says Dick. Researchers are now racing to identify tumor-forming stem cells in skin, lung, pancreatic, ovarian, prostate, and many other cancers. "We simply need to know what the cells are that give rise to the tumor. It's an unknown for virtually all tumor types," says Tyler Jacks, director of the Center for Cancer Research at the Massachusetts Institute of Technology (MIT)."