As evident from the results of immune histochemistry staining, less Ki67‐positive and MMP‐2‐positive cells were observed in the tumours sections from hinokiflavone‐treated mice compared with the control mice (Figures 6A and 6B), indicating that hinokiflavone impedes human breast cancer cells growth in vivo, which is consistent with the findings in vitro. Here, MMP2 is linked to breast cancer.