Some cancer cells are able to evade the body's adaptive immune response, particularly cancer-killing T cells, although the mechanisms underpinning the process are poorly understood. What is known is that dendritic cells (DCs) are a unique system of cells that 'turn on' T cells, priming them to fight cancer. New research by St Jude Children's Research Hospital has looked closely at how cancer cells and DCs interact and discovered that a fundamental energy-producing nutrient plays a key role in maintaining the immune system's ability to destroy tumors.