IL15 and neoplasm: Such strategies might include efforts to expand, differentiate, and maintain NK cell numbers with cytokines, such as IL-15 [175,176,177,178], and to stimulate those NK cell activation pathways most effective for the tumour type (either by checkpoint blockade and/or augmentation of activating pathways), as well as improving methods to target NK cells to tumour cells in vivo and efforts to neutralise immunosuppressive factors in the solid tumour microenvironment [12,179].