Compared with EVs from other tumors, EVs from metastatic BC often have distinct expression levels of biomarkers such as HER2, Annexin A2, ANGPT1, and insulin-like growth factor receptor, which aid in BC liquid biopsy; however, these biomarkers cannot fully encompass the cargo of hypoxia-induced EVs [7, 180]. This evidence concerns the gene ERBB2 and breast cancer.