CD274 and non-small cell lung carcinoma: As first-line therapy, pembrolizumab is approved as monotherapy for metastatic NSCLC with high tumor expression of PD-L1 (tumor proportion score [TPS] of ≥50%), and in combination with pemetrexed and carboplatin for metastatic NSCLC with nonsquamous histology regardless of PD-L1 expression level.