Importantly, these promising preclinical data of MMP-9 and -14 inhibitory monoclonal antibodies in HER2-positive breast cancer or TNBC mouse models showed that the anti-tumor effects of MMP inhibitory antibodies are associated with disruption of the immunosuppressive TME, indicating that the use of MMP inhibitors in combination with immunotherapy could improve the efficacy of immunotherapy in breast cancer. Here, MMP9 is linked to breast cancer.