Besides, it is reported that the PD-1 expression level in M2 macrophages is negatively correlated with the anticancer activity, while PD-1/PD-L1 blockage in vivo is shown to enhance macrophage phagocytic capacity, suppressing tumor growth and prolonging the survival period of tumor bearing mice (Gordon et al., 2017; Hutchinson, 2017). The gene discussed is PDCD1; the disease is neoplasm.