A few weeks ago I blogged about a Japanese researcher's piece in Nature, in which she claimed to have induced pluripotency in mouse blood cells simply by immersing the cells in an acid bath for a half-hour. It now emerges that the researcher, Haruko Obokata, may not have done this after all. The RIKEN center in Kobe announced on Friday that it is investigating "alleged irregularities" in her work. Questions have been raised about the use of duplicate images across several of her papers, and about numerous unsuccessful attempts to duplicate her results. Obokata is not answering press inquiries. The jury is very much still out: the failures to duplicate her results may simply be due to the complexity of her protocol and the character of the particular cells she used. The business about duplicate images may simply have been a mistake. Read the latest from Nature on the matter, and stay tuned.