IL15 and neoplasm: Third, we find that during weeks 5 through 7 post tumor implantation, IL-15, a pro-inflammatory and immune-activating cytokine that promotes survival, differentiation, proliferation, and activation of natural killer (NK), CD8+ T cells, and B cells69–75, showed a statistical increase in tumor-bearing mice that responded to treatment (long-term survivors) compared with tumor-bearing mice that failed treatment (non-survivors) (Fig. 4c, d, right panel, Supplementary Table 7) or with tumor-bearing mice vehicle control (Fig. 4c, d, middle panel, Supplementary Table 7).