CD274 and non-small cell lung carcinoma: The results of KEYNOTE 024 show that (13), compared with traditional chemotherapy drugs, OS and PFS treated with pembrolizumab are better for patients with advanced NSCLC with high expression of PD-L1 (≥ 50%), and when PD-L1 expression < 50%, the efficacy of immunotherapy is equivalent to that of traditional chemotherapy drugs.