It’s a compelling theory that emerged over 40 years ago.
Now studies by three teams of scientists are supporting a theory about why some cancers return - after they’ve seemingly been wiped out.
The findings show tumours contain a pool of cancer stem cells that can multiply and seed their regrowth.
If that’s true scientists will need to find a way to kill those stem cells while also attacking the rest of the tumour.
The studies on stem cells re-populating cancer were done on mice and are published online by the journals “Nature” and “Science.”