MMP9 and Myocardial fibrosis: Elevated expressions of the myofibroblast marker, α-SMA (alpha-smooth muscle actin) and the fibrosis markers including MMP9 and collagen type I (collagen I), were observed in T2DM mice that underwent MI surgery which exhibited significantly increased myocardial fibrosis compared to the T2DM-only group as shown in Figures 2J–O.