MMP9 and invasive breast carcinoma: Interestingly, in another study by Chen and colleagues, aimed at the analysis of the gene interaction network in patients with breast invasive carcinoma, several genes characteristic of EMT were elevated two- to threefold (MITF, TCF4, SNAI2, ZEB2, ZEB1, GNG11) in high-SEMA6D expression patients, while another key tumor metastatic promoter, matrix metallopeptidase 9 (MMP-9), was dramatically reduced [116].