For unresectable or metastatic disease, immune checkpoint inhibition (ICI) with the programmed cell death protein 1 (PD-1) inhibitor pembrolizumab or the programmed cell death 1 ligand 1 (PD-L1) inhibitor avelumab have replaced chemotherapy as first-line systemic therapy (2–4). Here, PDCD1 is linked to metastatic neoplasm.