Increased peripheral MMP-9 levels have also been reported to be implicated in hemorrhagic transformation after ischemic stroke (Rosell et al., 2008), ischemic stroke severity and infarct volume (Rosell et al., 2005; Demir et al., 2012), and poor prognosis of AIS (Ramos-Fernandez et al., 2011; Gori et al., 2017; Zhong et al., 2017). The gene discussed is MMP9; the disease is ischemic stroke.