UBE2D2 and breast cancer: Studies indicate that in vitro transduction of circ‐UBE2D2 via exosomes can enhance resistance to tamoxifen in breast cancer, with recent findings showing circ‐UBE2D2 expression being 20‐fold higher in MCF‐7/TAM‐R‐Exo compared with MCF‐7/Par‐Exo.760