For example, matrix metalloproteinases ('MMP') -9 (MMP-9) and -13 (MMP-13), derived in part from astrocytes may contribute to post-ischemic BBB dysregulation [55-57] and MMP-9 inhibition partially protects against ischemic stroke, decreasing infarct size and BBB breakdown. Here, MMP9 is linked to ischemic stroke.