In conclusion, this study showed the feasibility of staining PD-L1 in cell blocks from NSCLC patients, which is highly consistent with resected specimens when samples contained more than 400~500 cancer cells, suggesting cytological cell blocks may be a suitable surrogate for evaluating PD-L1 expression in cases that have a sufficient number of tumor cells. This evidence concerns the gene CD274 and non-small cell lung carcinoma.