Tumor Brake (image) University of California - San Diego Share Print E-Mail Caption The molecular "brake" known as PD-1 can bind and neutralize the same tumor cell, instead of an opposing tumor cell. Credit Hui Lab, UC San Diego Usage Restrictions Must be used in conjunction with Cell Reports paper on PD-L1 processes. 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.