IL15 and neoplasm: according to the results of NK cell cytotoxicity assay in the two groups, the highest cell lysis ability was reported in 5:1 ratio and 24 h after co-culture with K562 tumor cells, as 94.22 ± 1.93 (Fig. 5A-left, B) and 87.3 ± 3.45 (Fig. 5A-right, B) in the groups treated with IL-15 and IL-15/Hsp70 respectively.