MMP9 and diabetes mellitus: The LV expression of fibrotic marker genes, i.e. alpha-smooth muscle actin (αSMA), type I collagen (col1), type III collagen (col3), type IV collagen (col4), connective tissue growth factor (CTGF), matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9), was comparable between DM and Cn mice.