To explore whether down-regulated circUBE2K regulates BC growth in vivo, T24 cells transfected with scramble shRNA (sh-NC), shRNA targeting circUBE2K (sh-circUBE2K), shRNA targeting circUBE2K with miR-516b-5p inhibitor (sh-circUBE2K+inhibitor) and shRNA targeting circUBE2K with ARHGAP5 overexpression vector (sh-circUBE2K + ARHGAP5) were injected into nude mice subcutaneously and measured. Here, ARHGAP5 is linked to breast cancer.