New Role for a 'Foxy Old Gene' (IMAGE) University of Pennsylvania School of Medicine Caption Liver cells from mice that do not express FOXA2 (Mutant mice accumulated bile salts and failed to detoxify them properly, which resulted in liver damage.). The liver cells in this image show an accumulation of proteins that are used by cells to degrade unwanted substances. Credit Klaus Kaestner, Ph.D., University of Pennsylvania School of Medicine; Nature Medicine 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.