In the phase II KEYNOTE-059 study for patients with advanced G/GEJ adenocarcinoma at the third or later lines of treatment (n = 259), pembrolizumab treatment provided an ORR of 15.5% for patients with PD-L1-positive tumors (CPS ≥ 1), while it was 6.4% for those with CPS < 1 as determined via PD-L1 IHC 22C3 pharmDx [74]. This evidence concerns the gene CD274 and adenocarcinoma.