This is especially interesting since NKG2D can bind stress- or infection induced ligands of the non-classical MHC-I related molecules H60, RAE1, and MULT in mice or MIC-A/B and ULBP1-ULBP6 in humans and while these molecules are absent on healthy cells, they are often expressed by tumor cells (121–124) (Figure 1A). This evidence concerns the gene KLRK1 and neoplasm.