In supporting the critical role of HPK1 for the generation and maintenance of effective cytotoxic and memory CD8+ T cells by facilitating the optimal expansion and effector function of CD8+ T cells, we observed that HPK1 KD CD8+ T cells displayed greater activation status with higher CD69 expression upon being primed with tumor cells, along with markedly higher levels of IFNγ and TNFα release with ex vivo re-stimulation. This evidence concerns the gene MAP4K1 and neoplasm.