ERBB2 and breast cancer: Unlike certain tumors such as non‐small cell lung cancer (NSCLC) and breast cancer, where multiple markers like EGFR, K‐RAS, T790M (for NSCLC), and ER, PR, HER‐2, Ki67 (for breast cancer) aid in molecular typing and guide individualized diagnosis and treatment, GC has only successfully utilized one molecular marker, HER‐2, for personalized treatment [5, 6].