IL-15/IL-15Rα fusion protein (IL-15 superagonist) can bind to the intermediate-affinity receptor complex of IL-2R/IL-15R β- and γ-chains in the absence of cross-presentation by IL-15Rα on neighboring cells and exhibit its increased stability, improving the in vivo anti-tumor efficacy of CAR-NK cell therapy [241, 242]. Here, IL15 is linked to neoplasm.