Multifaceted nature of natural killer cells: Potential mode of interaction and shaping of stem cells

Natural killer (NK) cells are the key immune effectors with the ability to lyse stem-like/poorly differentiated tumor cells and mediate differentiation through their cytotoxic activity and via secretion of IFN-γ and TNF-α, respectively. In this book chapter, we describe the basic biology of NK cells and their function in cancer as well as the impact of the tumor microenvironment on NK cell function. Furthermore, we present a novel strategy for the expansion of allogenic NK cells, which results in the production of large numbers of highly functional supercharged NK cells. Moreover, we discuss the recent advances in the application of NK cells in cancer immunotherapy. The combination of standard anticancer treatments with recently established immunotherapeutic approaches with NK cells should provide the optimal conditions for the eradication of tumors.