Previous studies have revealed the use of PD-L1 on tumor cells as a potential biomarker to identify patients with non-small-cell lung cancer who are most likely to benefit from PD-1/PD-L1 blockade therapy (i.e., pembrolizumab, atezolizumab, and nivolumab) [70–73]. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.