Tumor-associated macrophages (TAMs) secrete inhibitory cytokines, such as interleukin-6 (IL-6), IL-10, transforming growth factor β (TGF-β), and prostaglandin-E, which inhibit NK cell activity and the activation and proliferation of T cells and induce T cell apoptosis, thereby downregulating the expression of MHC and changing TAMs to the M2 phenotype, resulting in immunosuppression (3). The gene discussed is IL6; the disease is neoplasm.