MMP9 and Moyamoya disease: Several studies have reported that MMPs play an important role in vascular tissue remodeling during stroke recovery.27–29 Furthermore, our data suggest that the increase in MMP-9 levels in the patients with successful revascularization is associated with previous findings that increased the level of MMP-9 as an important angiogenic factor in patients with moyamoya disease.30,31 Therefore, we believe that a higher level of MMP-9 is observed in cases showing sufficient revascularization, which is triggered by the initial hypoxic insult.