MT1-MMP enhances focal proteolysis [31] and experimental metastasis [32], is associated with MMP-2 activation in lung carcinoma [33] and invasive human breast cancer cell lines [34,35], and is over-expressed in high-grade gliomas, fibrosarcomas [36] and in carcinomas of the lung, stomach, head and neck [37]. The gene discussed is MMP2; the disease is breast cancer.