Increases in both the MMP-2 and MMP-9 concentrations and activity assessed in the vessels or in the plasma of hypertensive animals or humans are apparently not accompanied by corresponding increases in the activity of endogenous MMP inhibitors (the tissue inhibitors of matrix metalloproteinases), thus revealing imbalanced MMP activity in hypertension [77,85,86,88]. The gene discussed is MMP9; the disease is hypertensive disorder.