CD274 and metastatic squamous cell carcinoma: According to the European Society for Medical Oncology guidelines for non-oncogene-addicted metastatic non-small-cell lung cancer (NSCLC), patients with metastatic squamous-cell carcinoma (LUSC) or metastatic non-squamous NSCLC with performance status 2 and PD-L1 < 50% may receive single-agent chemotherapy with gemcitabine (GEM), docetaxel (DOC), or vinorelbine.