PDCD1 and neoplasm: ICs such as cytotoxic T‐lymphocyte associated protein 4 (CTLA‐4) and programmed death‐1 (PD‐1) expressed on T‐cells, and its ligand programmed death‐ligand 1 (PD‐L1) expressed on tumor and macrophages are critical for evading anti‐tumor immunity, with PD‐L1 expression often linked to immune evasion in tumors [15].