However, tumor/blood ratios in breast MT1-MMP- cells were significantly lower (0.51±0.15, 0.67±0.23, 0.81±0.24 and 0.80±0.11 at 1, 2, 4 and 7 days post-injection, respectively) than those for GBM/MT1-MMP+ tumors. The gene discussed is MMP14; the disease is neoplasm.