The effect of RKIP on MMPs expression is MMP1, 3, 10, and 13 specific as no significant differences in expression were observed with 14 other members of the MMP family as well as with three members of the TIMP (Tissue Inhibitor of MMP) family when the expression of RKIP was altered in 4T1 or 168FARN breast cancer cell lines Fig 1. This evidence concerns the gene TIMP1 and breast cancer.