KLRK1 and neoplasm: Various members of the NKG2DL and DNAM-1L families have been investigated using different cell systems (i.e., LCLs, EBV+ tumor cells, EBV− tumor cell lines transduced with EBV genes, EBV-infected B cells) and methods (staining of cell surface ligands either with a specific antibody or recombinant receptor, analysis of ligand mRNA level); few of these studies also tested susceptibility to killing by NK cells with or without blocking NKG2D or DNAM-1 axes by adding a receptor- or ligand-specific antibody (Table 2).