IFNG and neoplasm: We previously hypothesized and showed that decreases in CD16 receptors and inhibition of NK cell-mediated cytotoxicity could be a physiological programming for NK cells to switch their phenotype from CD16bright/+ to CD16low/− to increase secretion of IFN-γ and TNF-α, while decreasing their cytotoxicity to differentiate tumor cells that were selected by the NK cells [4].