The secretion of TGF-β1, matrixmetalloproteinase (MMP)2, and MMP7 by EAT is critical in promoting collagendeposition and fibrosis in the atrial tissue, contributing to atrial remodeling.Activin A enhances the expression of TGF-β1, thus stimulating theproduction of MMP2 and MMP7, which are involved in extracellular matrixremodeling, leading to fibrosis through the Smad signaling pathway [64, 65, 66, 67].Additionally, EAT is a major source of reactive oxygen species (ROS),contributing to oxidative stress in AF patients [68]. The gene discussed is MMP2; the disease is atrial fibrillation.