Regarding NK cell engineering, encouraging results have been achieved in different preclinical studies using SB or PB transposon system to introduce, (i) a CD33-CAR into cytokine-induced killer (CIK) cells in an AML xenograft model (109), (ii) a MSLN-CAR into NK-92MI cells in a pancreatic cancer model (110), (iii) a CAR-NK cells expressing both NKG2D CAR and IL-15 in an AML xenograft model (63). The gene discussed is KLRK1; the disease is acute myeloid leukemia.