how it started: > made using stem cells, looks like a textbook example of a real 14-day-old embryo. > It even released hormones that turned a pregnancy test p

how it started: > made using stem cells, looks like a textbook example of a real 14-day-old embryo. > It even released hormones that turned a pregnancy test positive in the lab. how it's going: > The researchers stress it would be unethical, illegal and actually impossible to achieve a pregnancy using these embryo models.