Notably, the documented expression of PD-L1 on tumors might influence the clinical decision of treating patients with immune checkpoint inhibitors in specific settings; indeed, strong expression of PD-L1 (≥50%) is required for prescribing pembrolizumab as first-line treatment for advanced NSCLC; similarly, a positive expression of PD-L1 (at least 1%) is necessary for the administration of pembrolizumab in second and further lines and for the administration of durvalumab after chemo-radiation with curative intent for locally advanced NSCLC. This evidence concerns the gene CD274 and non-small cell lung carcinoma.