An analysis of 34 patients with metastatic gastric or GEJ adenocarcinoma who were HER2-overexpression-positive revealed that the combination of trastuzumab with a modified FOLFOX-6 regimen (mFOLFOX-6) was better tolerated than the cisplatin plus fluorouracil regimen. Here, ERBB2 is linked to gastroesophageal junction adenocarcinoma.