Recently, ICIs are introduced as promising immunotherapeutic biomolecules, which have shown hopeful clinical outcomes in treatment of various cancers, as shown by monoclonal antibodies (mAbs) blocking cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4), programmed cell death ligand 1 (PD‐L1) and programmed cell death protein 1 (PD‐1).69, 70. Here, PDCD1 is linked to cancer.