Furthermore, NK cells secrete pro-inflammatory cytokines and chemokines (such as IFN-γ, TNF-α, IL-6, granulocyte–macrophage colony-stimulating factor (GM-CSF) and CCL5) that might exert direct anti-tumor activity in addition to promoting innate and adaptive responses (Guillerey et al. 2016). This evidence concerns the gene IFNG and neoplasm.