CD274 and gastric cancer: In the KEYNOTE-585 (NCT03221426) and MATTERHORN (NCT04592913) trials, the addition of PD-1/PD-L1 inhibitors to chemotherapy is being evaluated in a perioperative setting, and the ATTRACTION-5 (NCT03006705) trial is investigating an adjuvant therapy with nivolumab plus S-1/CapeOX for Stage III gastric cancer patients.