ERBB2 and breast cancer: In the past ten years, the research on the heterogeneity of breast cancer has made great progress, and a series of treatment methods has been proposed for breast cancer with different molecular phenotypes [1].The classification of luminal A (hormone receptor positive (HR+)/human epidermal growth factor receptor-2 (HER2)−, and low levels of protein Ki-67), luminal B (ER+, progesterone receptor (PR)+/−,HER2−), luminal B-like(ER+, PR+/−,HER2+), HER2-enriched (HR−/HER2+), and triple-negative breast cancer(TNBC) (HR−/HER2−) has entered clinical guideline [2].