KLRK1 and cancer: CAR-NK cells have been designed to target specific cancer antigens, which are highly expressed on most CRC, such as EpCAM, CEA, NKG2D ligands (through an NKG2D-CAR construct), and MUC-1 (39, 41), or to target antigens expressed only on a fraction of CRC patients, such as HER-2 (42) or Mesotelin (43).