ETS1 and breast cancer: To verify that circ_0000326 participated in the BC development via modulating the miR-338-3p/ETS1 axis, circ_0000326 siRNA and miR-338-3p inhibitor, or circ_0000326 siRNA and ETS1 overexpression plasmid was co-transfected into 5637 and T24 cell lines, respectively.