Concerning natural cytotoxicity of NKG2C+ NK cells towards tumor cells, several reports indicated efficient lysis of K562 and LCL 722.221 target cells devoid of HLA molecules by NKG2C+ NK cells, which was indistinguishable or higher when compared to the lytic efficiency of conventional NKG2C-negative NK cells [22,41]. This evidence concerns the gene KLRC2 and neoplasm.