Elevated serum levels of BDNF were found in some autoimmune diseases, such as Sjögren’s syndrome, systemic lupus erythematosus, and rheumatoid arthritis, and altered serum levels of BDNF was associated with disease activity or medication used in patients with these diseases [5,6,7,8]. The gene discussed is BDNF; the disease is systemic lupus erythematosus.