Elevated IL-6 levels have been implicated in conditions such as neuromyelitis optica spectrum disorder (NMOSD), multiple sclerosis (MS), Alzheimer’s disease, and neuropsychiatric lupus erythematosus (NPSLE), where it contributes to disease progression by enhancing immune cell trafficking into the CNS and promoting neuroinflammatory damage [197,198,199]. The gene discussed is IL6; the disease is neuromyelitis optica.