The incidence of diarrhea, which significantly affects the treatment tolerance in patients with GI tumors, was significantly lower than that reported in the reported JACOB study of pertuzumab, trastuzumab, and chemotherapy in HER2-positive GC patients (30.1% vs. 48%).20 Although diarrhea, rash, and thyroid function disorders were the most common irAEs, all were manageable and resolved with appropriate treatment. Here, ERBB2 is linked to gastric cancer.