MMP9 and Cerebral ischemia: Although MMP-9 inhibition has been proposed as a therapeutic strategy to attenuate BBB breakdown after cerebral ischemia (Dong et al., 2009; Chaturvedi and Kaczmarek, 2014), animal studies showed that MMP-9 is required for neurovascular remodeling and adaptation in the chronic phase after stroke (Zhao et al., 2006).