Colony of Human Embryonic Stem Cells (IMAGE) Ecole Polytechnique Fédérale de Lausanne Caption Colony of human embryonic stem cells that was exposed to a microfluidic gradient of a morphogen (BMP4), resulting in the establishment of different cell types arranged in layers. Credit Andrea Manfrin, EPFL Usage Restrictions Media purposes only. Commercial usage restricted; by permission only. License Licensed 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.