PDCD1 and neoplasm: Interestingly, high-dimensional profiling studies of immune cell populations infiltrating sarcomas of mice treated with anti-PD-1 mAbs, alone or in combination with anti-CTLA-4 mAbs, revealed Mn/macrophage remodeling in the tumor microenvironment, providing compelling support to the hypothesis that successful immune checkpoint therapy favors the generation of TAMs with an M1-like pro-inflammatory/anti-tumor phenotype while decreasing the induction of TAMs with an M2-like immunosuppressive phenotype [145].