TIMP2 and breast cancer: As others have previously shown that TIMP-2 can modulate rapid ERK activation by MT1-MMP expressing breast cancer cells [24, 25], we utilized conditioned media (CM) that contained high levels of TIMP-2, or ALA + TIMP-2 (a TIMP-2 mutant that cannot inhibit MMPs enzymatic activity, but which has been shown to still bind cell surface MT1-MMP and upregulate ERK activation [24, 46]) to test this parameter.