[Yaelle]

The researchers have already discovered one such protein — found mainly in embryos, placentas and tumours

Helloooooo! Every baby comes with a PLACENTA that is thrown away (sorry, Tom Cruise)! Each placenta must have a lot more stem cells than the 5-celled embryo. Why choose to kill a baby instead of making use of placental cells?

[Cobra64]

I thought so too. I don't get it.