PPBP and neurosyphilis: The levels of CCL24 (P = .0185), CXCL7 (P < .0001), CXCL13 (P < .0001), CXCL10 (P < .0001), and CXCL8 (P < .0001) in the CSF of neurosyphilis patients were higher than those in the CSF of patients without neurosyphilis (Figure 1D).