Comparisons of assay concordance have largely been limited to small retrospective studies [23,24], although a head-to-head comparison of both the Dako 28-8 and 22C3 assays derived from 362 gastric cancer tumour samples has shown that the percentage of PD-L1 positivity using the former antibody is twice as high as that of the 22C3 assay at various cut-offs (CPS ≥ 1: 70.3 vs. 49.4%, p < 0.001; CPS ≥ 5: 29.1 vs. 13.4%, p < 0.001; and CPS ≥ 10: 13.7 vs. 7.0%, p = 0.004) [25]. The gene discussed is CD274; the disease is gastric cancer.