IFNG and neoplasm: Another important function of NK cells is the production of cytokines, such as Interferon gamma (IFN-γ) and Tumor necrosis factor alpha (TNF-α); these cytokines also act as promoter agents of apoptosis in tumor cells, or they recruit and activate other cells of the immune response, such as monocytes/macrophages, dendritic cells, T cells, and B cells [7,8].