In COVID-19-associated ON, all serum samples were negative for AQP4 and GFAP antibodies, four (33.3%) patients were MOG-IgG-positive (titres were 1:100 in three patients and 1:32 in one patient), and one patient was CRMP5-IgG-positive (titre, 1:10). The gene discussed is GFAP; the disease is COVID-19.