KLRK1 and leukemia: Using NKG2D-Fc soluble protein to block the NKG2D ligands on target cells also abrogated the enhanced cytotoxicity of CAR-iNKT cells vs CAR T cells, further confirming the role of NKG2D in the differential reactivity of CAR-iNKT cells vs CAR T cells against leukemia (supplemental Figure 5B).