The results showed that NRG1 levels were significantly lower in the RRMS, SPMS, NMO groups compared to healthy controls, with the most pronounced reduction observed in NMO, suggesting NRG1 may serve as a potential biomarker for differentiating NMO from MS, especially in cases where traditional diagnostic criteria are inconclusive. The gene discussed is NRG1; the disease is neuromyelitis optica.