Diagram of the Colon (IMAGE) University of Zurich Caption This is a schematic representation of the large intestine with GLI1-positive cells in the stem cell niche (bottom, green). Credit Bahar Degirmenci, UZH Usage Restrictions None 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.