BDNF and ischemic stroke: When human umbilical mesenchymal stem cells were used to cure ischemic stroke in rats, implanted WJ-MSCs were shown to survive in the infarct cortex for at least 36 days and released neuroprotective and growth-associated cytokines including BDNF, platelet-derived growth factor-AA, angiopoietin-2, CXCL-16, and neutrophil-activating protein-2 [53].