Microclusters (IMAGE) University of California - San Diego Caption A fluorescent microscope image depicts the spatial pattern of an immunoreceptor (red) and its effector molecules (green) at the plasma membrane of a simulated T cell. Credit Hui Lab, UC San Diego Usage Restrictions Must be used in conjunction with Science Immunology paper on PD-1 research. 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.