Two phase III trials have demonstrated that adding zolbetuximab, a monoclonal antibody targeting CLDN18.2, to first-line chemotherapy [FOLFOX or capecitabine and oxaliplatin (CAPOX)] can significantly prolong OS in patients with CLDN18.2-positive, HER2-negative gastric cancer (7, 8). The gene discussed is ERBB2; the disease is gastric cancer.