Researchers have shown that excessive ROS induced by oxidative stress can up-regulate the activity of MMP family proteins such as MMP-2, activate mitogen-activated protein kinase signaling pathway [24] and inactivate NO secreted by vascular endothelial cells [25], thus causing metabolic disorders in myocardial cells and promoting synthesis and secretion of collagen. The gene discussed is MMP2; the disease is metabolic disease.