Dramatic retraction adds to questions about stem cell research

Researchers admit mistakes and question whether STAP cells exist

SEEING DOUBLE  Scientists now doubt their own earlier claims about an easy method to make stem cells. Among the errors identified in their papers were two pictures of a single embryo created from STAP cells (green) that had been represented as depictions of two different embryos (large image with placenta, inset without placenta). 

H. Obokata et al/Nature 2014

Rising doubts about easy-to-make stem cells have hit a crescendo: The researchers who claimed to have discovered STAP cells have pulled their papers from the journal Nature.