Immune cells enter tissues (IMAGE) Institute of Science and Technology Austria Caption Macrophages, a type of immune cell (purple), utilize the division of a tissue cell (green) to invade tissues. Credit © Maria Akhmanova/ISTA Usage Restrictions - License Original 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.