HeX-Embryoid model (IMAGE) University of Pittsburgh Caption Top-down view of circular heX-Embryoid model showing the interface of engineered induced pluripotent stem cells (iPSCs) forming the green outer layer and non-engineered iPSCs forming the inner layer where processes that mimic early embryonic organization will occur. The cells surrounding this circular area are similar to the embryonic yolk sac. Credit Mo Ebrahimkhani and Joshua Hislop Usage Restrictions For use with embargoed release License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.