MMP9 and ischemic stroke: In ischemic stroke, HSP70 exerts neuroprotection by inhibiting mitochondrial apoptosis via Bcl-2 upregulation and caspase-3 suppression while concurrently stabilizing the blood–brain barrier (BBB) through matrix metalloproteinase-9 (MMP-9) inhibition (Doeppner et al., 2017).