While the induction of this tumor-suppressive macrophage subtype represents the most commonly accepted functional and phenotypic change of an immune cell that enters a solid tumor, other effector cells have also been demonstrated to undergo functional changes upon interaction with the tumor microenvironment: Reduction in the expression levels of activating receptors such as NKp30 and NKp46 is a consequence of NK cell and tumor cell interaction in several entities [8, 9]. This evidence concerns the gene NCR1 and neoplasm.