However, It is important to note that the lack of standardization for PD-L1 IHC in terms of the specificity and reproducibility of the available anti-PD-L1 antibodies, the different staining techniques (manual versus automated), the definition of PD-L1 “positive” tumor (cell surface versus cytoplasmic expression, by tumor cells only or by other cells in the tumor milieu, the threshold of positive cells), the interpretative subjectivity, as well as including patients with different tumor grades− could be the explanation of these discordant results. This evidence concerns the gene CD274 and neoplasm.