The expression of hsa_circ_0058514 from extracellular vesicles was also detected in EVs extracted from the serum-free culture medium of normal breast ductal epithelial MCF-10a cells, and three different BC cell lines including hormone receptor-positive MCF-7 cells, SK-BR-3 cells with Her-2 overexpression, and triple-negative BT-549 cells (Figure 5C). The gene discussed is ERBB2; the disease is breast cancer.