Folding Poisons (IMAGE) University of Freiburg Caption Toxins produced by the bacterium Clostridium difficile penetrate the intestinal cell with the help of the protein known as TRiC. Credit Source: Klaus Aktories Usage Restrictions the image may only be used with appropriate caption or credit. 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.