In the present study we assessed the frequency of MOG-IgG as assessed by means of a live-cell CBA [17] (i) in a large series of samples from predominantly Caucasian patients sent in for AQP4-IgG and MOG-IgG testing and (ii) in a well-defined cohort of Caucasian control patients with multiple sclerosis (MS) and other inflammatory CNS disorders as well as in healthy controls (N = 614). This evidence concerns the gene AQP4 and myeloid sarcoma.