At first, such cells had to be extracted from embryos, an ethically dodgy process if those embryos were human. Then a way of making them from skin cells was invented. This, though, involves fiddling about with proteins called transcription factors, and is finicky. So when, in January, Nature published a pair of papers describing a simpler way of making them, people around the world sat up. In these papers Haruko Obokata of the RIKEN Centre for Developmental Biology in Kobe, Japan, and her team, claimed to be able to create pluripotent cells by exposing ordinary, non-stem cells to weak acids, physical squeezing and some bacterial toxins