Uruga et al. compared the PD-L1 (clone E1L3N, Cell Signaling) expression in primary tumor and metastatic lymph nodes in 66 cases of lung adenocarcinoma and found that up to 38% of cases showed discrepant PD-L1 expression between primary tumor and paired metastatic lymph nodes, raising the possibility of an heterogeneous intertumoral PD-L1 expression; however, after dichotomizing cutoffs at 1% and 50% of cells, PD-L1 resulted to be concordant respectively in 74% and 88% of cases [19]. This evidence concerns the gene CD274 and lung adenocarcinoma.