KLRK1 and neoplasm: At the same time, our results support the classical view that NKG2D can participate in immune surveillance of cancer by recognizing NKG2D ligands on tumor cells to induce NK cell activation and tumor cell killing (Diefenbach et al., 2000; Cerwenka et al., 2001; Diefenbach et al., 2001; Jamieson et al., 2002; Guerra et al., 2008).