Although selective targeting of MMP-9 with monoclonal antibody in UC or CD patients did not induce a significant symptomatic or endoscopic response [50,51], a result that may be attributable to the duality of MMP-9 function depending on the biological process or stage of inflammation [52], MMP-9 was reported to be a target of miR146a in human breast cancer [53]. This evidence concerns the gene MMP9 and breast cancer.