IL15 and neoplasm: Despite preserving a higher proportion of early/central memory subsets that mediate improved tumor immunity in mice [45, 83], transfer of Vγ2Vδ2 T cells expanded with IL-15 inhibited PC-3 tumor growth in NSG mice identically to equal numbers of Vγ2Vδ2 T cells expanded with IL-2 (Fig. 7).