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Sometimes even the best-known stories have hidden subplots. This January, Nature published two papers describing an astonishing new way to make stem cells: simply grow blood cells from adult mice in acidic media.1,2 The researchers behind the work—a team from the RIKEN Center for Developmental Biology in Japan and Harvard Medical School—called it stimulus-triggered acquisition of pluripotency, or STAP. These stress-induced stem cells were even more malleable than induced pluripotent stem cells (iPSCs), and, even better, they could be produced without the addition of transcription factors. Naturally, the press was abuzz with the promise of STAP to accelerate stem cell research. But in the less well-lit corners of the Web, some were already raising doubts.
Leading the way was Paul Knoepfler, a stem cell researcher ...
