CTCs were detected in 80% of patients, with levels ranging from 2 to 256 CTCs/4 ml. From 71 samples with matched tumour tissue and CTCs, 6 patients (8%) showed ≥1 PD-L1-positive CTCs and 11 patients (15%) showed ≥1% PD-L1-positive tumour cells in tumour tissue with 93% concordance between tissue and CTCs (sensitivity = 55%; specificity = 100%). Here, CD274 is linked to neoplasm.