All 565 patients with a CLDN18.2-positive (≥75% of tumor cells with moderate-to-strong CLDN18.2 expression), HER2-negative, previously untreated locally advanced unresectable or metastatic gastric or GEJ adenocarcinoma were randomly assigned to mFOLFOX6 combined with zolbetuximab or placebo. Here, ERBB2 is linked to gastroesophageal junction adenocarcinoma.