BDNF and ischemic stroke: In both the early and late stages following ischemic stroke, anti-inflammatory M2 microglia are considered to be the major effector cell with the potential to counteract pro-inflammatory reactions by producing anti-inflammatory factors (IL-4, IL-10, IL-13, or transforming growth factor-β (TGF-β)) [30] as well as promote tissue repair and neurogenesis by producing insulin-like growth factor-1 (IGF1), BDNF, and NGF [97, 98].