In mouse models, compared to mice that received conventional CAR-NK cells, mice treated with IL-15-secreting CAR-NK cells exhibit high plasma concentration of IL-15, high proliferation and persistence of CAR-NK cells, and more tumor shrinkage (Christodoulou et al., 2021a; Guo et al., 2024; Van den Eynde et al., 2024; Christodoulou et al., 2021b). The gene discussed is IL15; the disease is neoplasm.