Various immune checkpoints are the mature targets in tumor immunotherapy, like PD1/PD-L1 (Programmed Cell Death 1/ Programmed Cell Death Ligand 1), CTLA4 (Cytotoxic T-Lymphocyte Associated Protein 4) and LAG3 (Lymphocyte Activating 3), are in ongoing clinical trials [1]. Here, PDCD1 is linked to neoplasm.