[17] Arrays were then performed to quantify RNA isolated from these tumor cell populations in IL-15+/+ and IL-15−/− tumors (FIG. 3A). The average results obtained from two independent tumors of each genotype identified transcripts that were affected by the absence of IL-15 (FIG. 3B, FIG. S3). Within the malignant CD16/32HI population, IL-1α and its receptor IL-1r1, IL-1α-regulated cytokines ccl3 (aka: MIP-1a) and cxcl3 (aka: MIP-2b,Gro-3), and IL-1 family member 9 were among the transcripts most highly elevated in the absence of IL-15. This evidence concerns the gene IL15 and neoplasm.