It has been reported that the inflammatory cytokine IL-6 is raised in the CSF of NPSLE patients compared with SLE patients without CNS symptoms [40], and this could be confirmed also in the present CSF samples (49 ± 68 pg/ml in NPSLE patients versus 26 ± 44 in SLE patients without CNS symptoms; P < 0.05). This evidence concerns the gene IL6 and systemic lupus erythematosus.