MMP9 and cancer: More recently, in an immunohistochemical study we have demonstrated that tissue expression of MMP-9 was significantly higher in moderately (G2) and poorly (G3) differentiated tumors than in well differentiated (G1) cancers, as well as in advanced Dukes stages compared with Dukes stage A. We have shown diffuse strong MMP-9 expression in both tumor and stromal cells.