KLRK1 and neoplasm: These findings strongly support that tumor exosomes can deliver TGF-b to the surface of NK cells that is engaged with TGFβRI/II and subsequently upregulates SMAD 2/3 phosphorylation and decreases Tbet expression levels, leading to the decreased NKG2D expression and abrogated cytolytic activity in NK cells [23, 64] (Fig. 3).