KLF10 binds to the promoters of SMAD2 and TGF‐β1, and more importantly, it serves as a positive feedback loop for regulating TGF‐β signalling by inducing the expression of SMAD2.39 Based on this case, we assume that the MMP‐9 induced the transcriptional increases in SMADs in breast cancer cell lines may link with activation of TGF‐β/SMAD signalling and KLF10. This evidence concerns the gene MMP9 and breast cancer.