MMP9 and breast cancer: Surfactin can suppress the proliferation of the human colon carcinoma cell line LoVo (Kim et al. 2007), suppress TPA-induced breast cancer cell invasion through the inhibition of MMP-9 expression (Park et al. 2013b), and kill the human breast carcinoma cell line MCF-7 through a ROS/JNK-mediated mitochondrial/caspase pathway (Cao et al. 2010).