AQP4 and neuromyelitis optica: Among NMOSD patients receiving different dosages of MMF, there were no significant differences between the baseline characteristics including age, female percentage, complete NMO patient percentage, aquaporin-4 antibody positivity, age at disease onset, duration of MMF treatment, treatment-naïve patients, disease duration, attack number, ARR and EDSS before receiving MMF (Additional file 1: Table S1).