Dr. Shinya Yamanaka invented a time machine. That's how he and his colleagues sometimes describe their work. They take full-grown cells from humans and they regress them - they send them back in time, to their earliest, embryonic state - and then they coax them into the future, into totally new types of cells. Last week, Yamanaka was awarded the Nobel Prize in physiology or medicine for his work creating induced pluripotent stem (IPS) cells - cells that are genetically engineered into blank slates, allowing them to be transformed into any type of cell in the body. His technique could allow scientists to explore human diseases like they never have before, or help doctors regenerate tissue lost to injury or illness. Using his technology, scientists can now take a skin cell and transform it into a heart cell that will actually beat in a lab dish. Yamanaka's IPS cells, developed just six years ago, have the potential to revolutionize medical research, his peers say. Labs that never were able to access stem cells before can now make them, and the cells themselves could be used to treat patients someday. They are already helping scientists study complex human diseases like Alzheimer's and autism. Everything was turned upside down with Shinya Yamanaka's work," said Dr. Arnold Kriegstein, director of stem cell research at UCSF. "It really has transformed the field. It made it possible for laboratories all over the world, with very little investment, to start making stem cells."