Our immune system protects of our body by detecting and destroying cells that are potentially cancerous. Sometimes, our immune system fails to detect a problem, leading to cancer. In pediatric cancer, CD8 T cells fail to destroy cancer cells. CD8 T cells are white blood cells specialized in the detection and attack of cancer cells. Like us, CD8 T cells need to “eat” to stay alive, to move, and to function. Without nutrients, they can’t fight off cancerous cells. In cancer, there is a fight for nutrients between CD8 T cells and cancer cells. CD8 T cells have to quickly adapt to make sure they can maintain their protective functions. We know that CD8 T cells can rapidly switch from using nutrients to grow, to burning them to make energy, but we do not know how it is regulated. The aim of my project is to study how CD8 T cells know which nutrients are around them, and how they “choose” to switch between growing and burning. Why is it important? If we grow CD8 T cells in a laboratory setting, restrict their food, and re-feed them, they provide better protection against cancer. Understanding how CD8 T cells “eat” and use nutrients to grow or burn energy to kill cancer cells will help develop better therapies to treat pediatric cancer.