In the tumor microenvironment, macrophages inhibit NK cell activation receptors (NKG2D and NKP30) by secreting transforming growth factor-β, modulate chemokine receptor (CX3CR1) expression, and promote the expression of inhibitory receptors (ILT-2), which in turn reduces the release of cytokines (interferon-gamma and tumor necrosis factor-α) from NK cells (16). This evidence concerns the gene IFNG and neoplasm.