If metastatic disease is confirmed, treatment with a programmed cell death ligand 1 (PD-L1)-blocking agent (avelumab) or programmed cell death protein 1 (PD-1) inhibitor–based immunotherapy (pembrolizumab, nivolumab) should be used as a first-line treatment option.17, -19 Systemic chemotherapy with platinum (cisplatin, carboplatin) plus etoposide may provide benefit to patients who do not respond to PD-1/PD-L1 inhibitor–based immunotherapy. The gene discussed is PDCD1; the disease is metastatic neoplasm.