Hsu et al.20found that by regulating endogenous brain‐derived neurotrophic factor (BDNF) production, calycoyne isoflavone treatment could enhance the expression of BDNF/TrkB in the brain and make microglia cells change from active ameba state to static branch state, so as to improve ischemic stroke injury in mice. Here, BDNF is linked to ischemic stroke.