AQP4 and transient ischemic attack: As the basis for that mechanism, there are previous animal experiments that cytokine (interleukin‐1β) induces the activation of AQP4 through a the nuclear factor‐κB pathway in the rat brain (Ito et al., 2006), accelerated progression of cytotoxic brain edema was recognized in transgenic mice (AQP4‐ overexpressing) (Yang, Zador, & Verkman, 2008), and the absence of AQP4 was associated with decreased mortality and increased motor recovery after transient cerebral ischemia in AQP4‐knockout mice (Hirt et al., 2017).