Interestingly, Shen et al. reported that the downregulation of OC-2 mediated by chemotherapy-induced extracellular vesicle (EV) miRNA was thought to promote the stemness and chemoresistance of breast cancer, though the overexpression of OC-2 dramatically facilitated the growth of xenograft mammary tumors [14]. This evidence concerns the gene ONECUT2 and breast cancer.