It was demonstrated that NKG2D ligands (MICA, MICB, and ULBP) carried by tumor-derived EVs bound to the inhibitory receptor, NKG2D, on the surface of NK cells, with delivering of inhibitory signals and blocking of anti-tumor cytotoxicity of NK cells (Clayton et al., 2008; Lundholm et al., 2014). Here, KLRK1 is linked to neoplasm.