CXCL13 is secreted by secondary lymphoid tissue, dendritic cells and lymph nodes and is involved in the regulation and migration of B-cells, correlating well with the concentrations of intrathecal B- and T-cells (21–23),and has been investigated as a biomarker for confirmed and asymptomatic neurosyphilis (18, 21–25). This evidence concerns the gene CXCL13 and neurosyphilis.