ERBB2 and gastric cancer: For the first-line treatment of HER2-negative advanced gastric cancer, the Checkmate649 study confirmed that nivolumab combination chemotherapy can bring significant survival benefits to patients and has become a standard treatment recommended by the National Comprehensive Cancer Network (NCCN) Guidelines version 2.2022 and the Chinese Society of Clinical Oncology (CSCO) guidelines 2021 (9).