CD274 and gastric cancer: In the KEYNOTE-059 trial, among the GC patients who received pembrolizumab treatment, PD-L1-positive patients showed a considerably high overall response rate (ORR) (15.5%) compared to PD-L1-negative patients (6.4%).19 In addition, patients with MSI-H tumours experienced higher ORR than patients with non-MSI-H tumours (MSI-H vs. non-NSI-H; 57.1% vs. 9.0%).