CD4 cell counts less than 200 cells/μL, serum RPR/VDRL titers ≥1:32 suggested a significant increase in the incidence of neurosyphilis, which needed to be addressed by further lumbar puncture examination.[19,20] In the present study, both the CD4 cell count and the percentage of CD4 cell count more than 200 cells/μL that were found in the neurosyphilis group were lower compared to the syphilis group. The gene discussed is CD4; the disease is syphilis.