Strikingly, Daher and the colleagues compared the retrovirus transfection of iC9.CAR19.CD28-z-2A-IL-15 (with IL-15) with CAR19.CD28-z (without IL-15) into UC-NK cells, and confirmed the feasibility of high-efficient CAR-NK cell generation and the persistence of in vivo antitumor activity in xenogeneic lymphoma models [41]. This evidence concerns the gene IL15 and lymphoma.