MMP2 and neoplasm: Then, considering that tumor cells can pass through the extracellular matrix (ECM) for migration, we measured the zymographic expression of MMP9 and MMP2 that belong to the metalloproteinases family involved in the degradation of ECM and found that the expression levels of MMP9 and MMP2 in the tumors of Pgrmc1 KO mice were decreased (p < 0.05, 74.6% and 91.4% compared with WT mice, respectively) (Fig. 3d).