Contamination blamed in STAP stem cell debacle

Investigation finds new form of flexible cells were really embryonic stem cells

Mouse embryo

Researchers who claimed to have grown a mouse fetus from stem cells made in acid baths were actually working with embryonic stem cells, an investigation finds.

H. Obokata

The discredited stem cells known as STAP cells were ultraflexible because they were really embryonic stem cells, a new report contends.