MMP2 and Myocardial fibrosis: The cardioprotective effect of HNG treatment on myocardial fibrosis and apoptosis was shown on aged mice, where HNG application significantly reduced apoptosis, collagen deposition in aged hearts, cardiac fibroblast proliferation and expression of MMP2 (Matrix Metallopeptidase 2), FGF2 (Fibroblast Growth Factor 2) and TGFB1 (Transforming Growth Factor Beta 1).