BM-MSCs have been shown to cross the blood-brain barrier and improve functional recovery after acute ischemic stroke in animal models (Chen et al., 2001; Lee et al., 2016), likely due to a paracrine effect by secreting neurotrophic, mitogenic, and angiogenic factors, including VEGF, BDNF, nerve growth factor, basic fibroblast growth factor, and insulin-like growth factor 1 (Eckert et al., 2013; Shichinohe et al., 2015; Stonesifer et al., 2017). Here, BDNF is linked to ischemic stroke.