Breast cell image (IMAGE) University of Cambridge Caption Immune cell exhaustion is observed in breast tissue from carriers of BRCA1 and BRCA2 mutations long before breast cancer develops. Credit Sara Pensa/University of Cambridge Usage Restrictions With credit 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.