MMP9 and neoplasm: Despite this, qPCR experiments and in situ hybridization demonstrated that expression of matrix metalloproteinase genes (mmp9, mmp13a and mmp14b) was strongly increased in krasG12D-expressing intestinal cells, a molecular clue for invasiveness of tumor cells (Fig. 3M-O and Fig. S4) (Hanahan and Weinberg, 2011).