MMP1 and breast cancer: For MMP-1, -8, -10, -11, -12 and -15 both, expression of proMMP and active MMP were significantly higher in breast cancer tissue compared to normal breast tissue (e.g. expression of proMMP-1 was higher in breast cancer tissue grade 2 (p = 0,0007) and grade 3 (p = 0,0027) when compared to normal breast tissue; Figure 4).