MMP2 and tumor of salivary gland: Corroborating our findings, the presence of MMP-2 and -9 in salivary gland tumors and in MEC has been demonstrated previously and correlated with higher rates of metastasis and disease recurrence, as the function of these proteases is to promote the degradation of various ECM components [4,38,39], thereby increasing the infiltrative capacity of tumor cells.