Clinical data have also shown that plasma and brain levels of MMP-9 are elevated in patients with acute ischemic stroke, and delayed tPA therapy causes a further increase in plasma MMP-9 in stroke patients (Horstmann et al., 2003; Montaner et al., 2003; Rosell et al., 2006; Castellanos et al., 2007; Kelly et al., 2008; Rosell and Lo, 2008; Barr et al., 2010). Here, MMP9 is linked to Stroke.