C21 (0.03 mg/kg/d IP) for 6 weeks post-MI: Improved MI-impaired cardiac function (echocardiography); Reduced cardiac interstitial fibrosis and TGF-β1 in LV; Decreased MMP2/9; increased TIMP1 and MMP9/TIMP1 ratio. The gene discussed is MMP2; the disease is Interstitial cardiac fibrosis.