MOG and myeloid sarcoma: While it is true that low-titer MOG-IgG values classified as false-positives are often reported in patients with MS, this is confounded by the fact that MS is likely the most common alternative diagnosis among patients being tested for MOG-IgG in clinical practice; the greatest proportion of false-positives is thus expected to be patients with MS, even if no predilection for MOG-IgG detection in MS exists.