CD274 and gastric cancer: In the independent validation cohort of pembrolizumab-treated patients with GC, the subgroup with PD-L1 positive staining (CPS ≥ 1) and HA − had showed the most favorable clinical response to pembrolizumab compared with other subgroups, with an ORR of 62.5% and a DCR of 93.8% (Table 2).