CXCL13 and systemic lupus erythematosus: Serum CXCL13 is positively correlated with the SLE Disease Activity Index (SLEDAI) (84, 144, 145), anti-double-stranded DNA (anti-dsDNA) antibodies titers, and prevalence of inflammatory arthritis, while it is inversely correlated with serum levels of complement factors C3 and C4 (146–148).