Similar results were observed in breast cancer cells, in which depletion of MT1-MMP also led to replication fork stalling and collapse.11 These data suggest the involvement of MT1-MMP in DNA repair may be generalized to tumors expressing the protein rather than tissue of origin, thus making MT1-MMP an intriguing target in invasive tumors undergoing radio- and chemo-therapy. This evidence concerns the gene MMP14 and breast cancer.