Lawrence Livermore National Laboratory (LLNL) scientists exploring the interaction between cancer cells and the extracellular matrix (ECM)—the “scaffolding” of organs—found that proteins in the ECM can dramatically impact the immune system’s ability to kill tumors. Researchers said the findings, published online in the journal Biomaterials, could represent a novel approach to studying immunosuppression found in many breast cancers and open new pathways of activating the immune system to target cancer.