AQP4 and neuromyelitis optica: Mice with conditional astrocyte-specific STAT3 knockout (STAT3 cKO; STAT3fl/fl × ALDH1L1-CreERT2) received tamoxifen induction, followed by the systemic NMO paradigm (AQP4-IgG or Ctrl-IgG), behavioral testing, and spinal cord histopathology (Figure 5E).