R-Spondin 1 -Treated Intestinal Tumor (IMAGE) University of Helsinki Caption R-Spondin 1 -treated intestinal tumor in the left upper part of the figure has disorganized pink nucleae (ß-catenin staining in red, Prox1 in white). APC staining on the luminal surface of normal epithelial cells is shown in green and their nuclei in blue; this staining is lacking from the tumor because of mutation in the APC gene. Credit Marianne Lähde Usage Restrictions Credits: Marianne Lähde 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.