CXCL12 and neuromyelitis optica: The concentration of CXCL12 was decreased in pOMS, N-methyl-d-aspartate receptor (NMDAR) encephalitis, pAnti-Hu/ANNA-1 paraneoplastic syndrome, and neuromyelitis optica (NMO), but increased in pMOG, adult AE, and neuropsychiatric systemic lupus erythematosus (NPSLE).