Besides through the CAR recognition of tumor surface antigens, CAR-NK cells can also recognize cancer cells through a variety of previously described receptors, such as natural cytotoxic receptors (NKp46, NKp44, and NKp30), NKG2D, and DNAM-1 (CD226), conferring a higher targeting efficacy compared to CAR-T cells. This evidence concerns the gene KLRK1 and cancer.