HER2‐targeted therapies, including antibodies (trastuzumab and pertuzumab), antibody‐drug conjugate (ADC), and tyrosine kinase inhibitor have significantly improved patient outcomes in breast and gastric cancer.[3] However, their applications in ovarian cancer are debatable and clinical evidences have demonstrated that patients with HER2‐positive ovarian cancer showed poor response to existing HER2‐targeted therapy.[4, 5] Recently, immunotherapy has been developed to combat advanced‐stage cancers in clinic. Here, ERBB2 is linked to gastric cancer.