MMP2 and Myocardial fibrosis: At the same time, TGFβ-1 affects the downregulation of the MMP2/TIMP2 and MMP9/TIMP1 ratios, promotes an increase in collagen fiber synthesis, changes the proportion of collagen fiber types, and increases the overall collagen fiber content, thus triggering ventricular remodeling and leading to myocardial fibrosis (8, 9, 42).