KLF5 and breast cancer: Meanwhile, it was urgent to define the relation between circEZH2 and KLF5, on the one hand, clinical BC samples from SYSUCC were used to reveal a positive correlation between circEZH2 and KLF5 (Fig. 6e), on the other hand, while circEZH2 was overexpressed or downregulated, RT-qPCR and western blot were taken to find that circEZH2 could upregulate mRNA and protein of KLF5 (Additional file 1: Fig. 1e-f).