TOP2A and cancer: Since doxorubicin exerts an anti‐cancer effect by binding to TOP2A and impeding DNA replication, we first verified the effect of doxorubicin on the expression of TOP2A and UBE2C.[33] As shown in Figure 3A and Figure S5A (Supporting Information), doxorubicin significantly inhibited the expression of TOP2A but had little effect on the expression of UBE2C in breast cancer cells.