Compared with palliative chemotherapy, pembrolizumab has been shown to prolong both progression-free survival (PFS) and overall survival (OS) in NSCLC patients with or without brain metastases who express programmed cell death ligand 1 (PD-L1) with tumor proportion score (TPS) ≥1%, achieving an intracranial response rate of 20%–30% (4, 5). The gene discussed is CD274; the disease is non-small cell lung carcinoma.