CD274 and gastric adenocarcinoma: In a large cohort of gastric adenocarcinoma patients, the percentage of PD-L1-positive samples at various CPS cut-offs for the 28–8 assay were approximately twofold higher than that of the 22C3 assay, with only moderate concordance between the 22C3 and 28–8 assays at CPS ≥ 5.