AQP4 and cold agglutinin disease: Autoimmune hemolytic anemia (AIHA), cold agglutinin disease (CAD) (summarized in this excellent review [61]), anti-acetylcholine receptor antibody-positive generalized myasthenia gravis (gMG) [62], anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis [63], and anti-aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (NMOSD) [64] are examples that reached both clinical and therapeutic interest.