Moreover, M2 macrophages exert pro-tumor function by producing cytokines, such as interleukin (IL)-10 and transforming growth factor (TGF)-β, and play an immunosuppressive effect by the expression of programmed cell death ligand (PD-L1) and PD-L2 directly inhibiting cytotoxic T cell functions (12). The gene discussed is TGFB1; the disease is neoplasm.