Chinese scientists do genetic engineering on human embryo

Are Chinese scientists playing God?

They're doing genetic engineering on human embryos.

If they are playing God, they need more practice.

Nature.com says they were only able to successfully replace genetic material 28-percent of the time.

Also, some unintended mutations took place.

The embryos they used are 'non-viable', meaning they would never result in a live birth.

And the research is meant to cure diseases.

But some are still worried about the ethical issues of genetic engineering.