Taking advanced NSCLC as an example, anti-PD-1/PD-L1 monotherapy can improve the tumor response and overall survival of patients with higher PD-L1 expression (KEYNOTE-024 study) [30], but not patients with low PD-L1 expression (CheckMate 026) [32], when compared with platinum-based chemotherapy. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.