CXCL12 and systemic lupus erythematosus: In a polish study including 61 lupus patients (66% of them were under immunosuppressive treatment with steroid and/or cytotoxic agents during the study), the serum level of CXCL12 was statistically higher in patients compared to healthy subjects but no correlation was found according to the activity of the disease (Robak et al., 2007).