CD274 and gastroesophageal junction adenocarcinoma: In 2017, the Food and Drug Administration (FDA) granted accelerated approval to pembrolizumab for patients with recurrent locally advanced or metastatic, gastric or gastroesophageal junction adenocarcinoma whose tumors express programmed death-ligand 1 (PD-L1) as determined by an FDA-approved test based on the clinical results of KEYNOTE 059 (NCT02335411) (1).