Our finding that INL swelling as measured by retinal OCT only occurred in the presence of both AQP4‐specific T cells and anti‐AQP4 antibodies but not in T‐cell‐mediated encephalomyelitis with either AQP4 or MOG as target antigens alone is in line with a loss‐of‐function of Müller cells, which play an important role in water and potassium homeostasis of the INL of the retina 37. The gene discussed is AQP4; the disease is encephalomyelitis.