CSF and paired sera: HIV, bacterial and parasitic infections, tuberculosis,autoimmune encephalitis and paraneoplastic encephalitis negativeSerum studies: Systemic lupus erythematosus, Sjogren syndrome, Bechet’s disease,sarcoidosis, and antiphospholipid antibody syndrome negative, Anti-MOG antibodies. The gene discussed is MOG; the disease is sarcoidosis.