Microphotographs of representative examples of PD-L1 protein expression according to histological subtypes of lung adenocarcinoma.

<p>(A) PD-L1 protein is expressed in tumor cell membranes (>50%) in 37.3% of solid predominant ADC (arrowheads). (B) In contrast, PD-L1 was not expressed in most lepidic predominant ADC (97.6%). (A and B, 20× magnification).