CD274 and lung adenocarcinoma: Tumour-cell programmed death-ligand-1 (PD-L1) expression has been associated with better outcomes under anti-PD-1 immunotherapy: a recent meta-analysis highlighted better odds ratios of ORRs for the 1%- and 5%-positive tumour-cell thresholds (respectively, 2.81, P = 0.0002; and 2.22, P < 0.00001).8 Moreover, because all studies reported significant response rates of PD-L1– melanomas,9 PD-L1–status determination is not mandatory for the prescription of these agents to melanoma patients, unlike lung adenocarcinomas.10