Of the MMPs, MMP-9 (gelatinase B) has been most prominently tied to BBB disruption following ischemic stroke degrading type IV and V collagens, which are significant components of the ECM’s basal lamina as well as tight junction proteins including occludin, claudins, and ZO-1 (Yang et al., 2020). This evidence concerns the gene MMP9 and ischemic stroke.