The most extensively utilized immunotherapy methods–like immunological checkpoint inhibitors–are responsible to reduce a variety of immune checkpoints in active tumor-specific T cells, including cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4) and programmed death 1 (PD-1)/Programmed death-ligand 1 (PD-L1) ICPis. Here, PDCD1 is linked to neoplasm.