IL37 and systemic lupus erythematosus: Compared to healthy subjects, increased circulating (serum and plasma) levels of IL-37 have been documented in various inflammatory and autoimmune conditions, including rheumatoid arthritis (18–24), ankylosing spondylitis (25), endometriosis (26–28), systemic lupus erythematosus (29–31), Guillain-Barré syndrome (32), Graves’ disease (33), and multiple sclerosis (34, 35), as well as in spinal cord injury (36) where its levels are frequently correlated with measures of disease activity.