Recently, the third interim analysis of KEYNOTE-811, which included locally advanced or metastatic HER2-positive gastric/GEJ adenocarcinoma, showed that pembrolizumab plus trastuzumab and chemotherapy showed remarkable improvement in complete (16.6% vs. 11.2%) and objective response rates (72.6% vs. 60.1%) compared with trastuzumab and chemotherapy. Here, ERBB2 is linked to gastroesophageal junction adenocarcinoma.