There is more spin in discussions of embryonic stem cells than in the average gyroscope. Even eminent scientists tend to glide over the disadvantages of their preferred cell type. But quite consistently throughout years of debate, four uses for these cells have been mentioned: curing dread diseases, testing drugs, doing genetic research, and benchmarking performance. What no scientist in favour of using them has ever mentioned is that someday they would no longer be needed.

Until now. Dr Rudolph Jaenisch, a leading and often-quoted researcher at the Massachusetts Institute of Technology, told the New York Times that scientists currently need embryonic stem cells to benchmark the performance of adult stem cells and induced pluripotent stem cells. But then he admitted that this would not be the case for ever. “Things are very much in flux,” he said. “We will probably need human embryonic stem cells for a while. And then we probably will not need them anymore.”  ~ New York Times, Aug 25