In patients with non-small-cell lung cancer, pembrolizumab (anti-PD-1 antibody) and atezolizumab (anti-PD-L1 antibody) used as first-line therapy may only be appropriate for patients with PD-L1 expression on ≥50% of tumour cells (in the US, pembrolizumab can also be used in patients with a high tumour mutational burden and PD-L1 expression on ≥1% of tumour cells) [2,5,6,7]. The gene discussed is CD274; the disease is non-small cell lung carcinoma.