CD274 and cancer: For ICI immunotherapy with some specific drugs as Pembrolizumab and Cemiplimab, the diagnostic companion of PD-L1 positive immunohistochemistry is a must, while for other drugs the PD-L1 assay is optional21,37–39, although it is classified as an imperfect biomarker for response prediction40, as shown that some patients with high expression of PD-L1 had no response to the ICI ́s therapy and some cancers with low expression of PD-L1 had a long lasting response40,41.