Stem Cell Endoderm (IMAGE) University of California - Berkeley Caption Pluripotent stem cells, created from human skin or mouse ear tissue, are shown here becoming endoderm cells. The endoderm is one of the three primary germ layers that ultimately contribute to the development of vital organs (liver, pancreas, etc.). The yellow highlights the Sox17 protein, expressed during endoderm development. Cell nuclei are shown in magenta. Credit Song Li Lab Usage Restrictions All rights reserved. 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.