MMP9 and myocardial infarction: Once activated, MMP-9 could act on and dissolve a wide range of MI-associated substrates, including ECM proteins (mainly collagen, fibronectin, laminin, thrombo-reactive protein, and tendon in C), non-ECM substrates (mainly various cytokines and chemokines, such as TNFα, IL-1β, TGFβ, and CXC motif ligands), and novel substrates (CD36 and citrate synthase) [109].