C3d (image) Michigan Medicine - University of Michigan Share Print E-Mail Caption When the C3d vaccine was added to a tumor, the cancer cells began to die (right). Tumor cells not given the vaccine continued to grow. Credit Michigan Medicine Usage Restrictions for use in stories about this research Share Print E-Mail 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.