PDCD1 and neoplasm: EVs from the WT cells, but not TβRII null, led to a reduced cytotoxicity of tumor-infiltrating T cells (IFNγ+ or GZMB+ of CD8+ cells) and an increased exhaustion of tumor-infiltrating T cells (IFNγ+, PD1+ or TIM3+ of CD8+ cells) (Fig. 6l).