The CSF concentrations of CXCL13 were remarkably increased in patients with neurosyphilis compared to patients with syphilis/non-neurosyphilis (χ2 = 21.802, P < 0.001) and patients with non-syphilis/non central nervous system (CNS) infection group (χ2 = 9.340, P = 0.009, Fig. 1b). Here, CXCL13 is linked to syphilis.