MMP13 and breast cancer: The predictive power of MMP/RKIP expression ratio for breast cancer relapse-free survival is apparently MMP type-specific as high MMP10 and low RKIP expression did not associate with poor survival S1 Fig These results implicate RKIP as a possible repressor of MMP13 expression in breast cancers and suggest that RKIP and MMP13 may be in the same regulatory pathway affecting cancer metastasis.