Our proposal will help to close the gaps described in the “Project overview”. We will achieve this through a highly innovative approach that combines clinical and basic research. By using clinically relevant samples, we will explore the mechanisms that may influence the fitness of δγ T-cells. This unique approach will allow us to gain new insights into δγ T cell biology and provide the basis for the development of δγ CAR-T cell products with improved functionality for the treatment of cancer. Our project is divided into three objectives: In the first objective, we will conduct a clinical study in relevant cohort of pediatric patients that will enable us to explore unique δγ T cell biology. In the second objective, we will examine phenotypes of δγ T cells to identify and better understand their unique immunobiology. As a third objective, we will evaluate the fitness and function of δγ CAR-T cells.