Although MRI-negative myelitis can be observed in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), lupus myelitis, and glial fibrillary acidic protein (GFAP) astrocytopathy, post-COVID-19 myelitis lacks specific biomarkers, complicating both diagnosis and treatment. The gene discussed is OMG; the disease is myelitis.