Further investigation of this hypothesis may show that γδ T cells were compared favorably with professional APCs such as DCs with respect to their advantage of expansion in vitro and direct activation by signals preferentially expressed on tumor cells, such as NKG2D ligands MIC A/B and ULBPs [22, 37, 38], and, thus, these cells may become a continual and renewable source of functional APCs. Here, KLRK1 is linked to neoplasm.