For ICBs’ monotherapy as third-line, pembrolizumab (a humanized anti-PD-1 IgG4 monoclonal antibody) was approved by the FDA for the treatment of locally advanced or metastatic gastric or gastroesophageal junction cancer (GC/GEJC) patients with PD-L1 positive tumors (Combined Positive Score (CPS) ≥1). The gene discussed is CD274; the disease is gastric cancer.