First, although PD-L1 expression in tumor tissue has been advocated as a standard for anti-PD1/PD-L1 immunotherapy and moderate concordance has been shown by previous studies in PD-L1 assay results, the results are still influenced by multiple factors such as intra-tumoral heterogeneity of PD-L1 expression, cellularity, and more three-dimensional cell clusters in cytology samples (19). This evidence concerns the gene PDCD1 and neoplasm.