CD14 and syphilis: The proportion of the intermediate monocyte (CD14++CD16+ monocytes) subsets was significantly elevated in syphilis patients compared to healthy controls (15.06 ± 10.75 vs. 5.52 ± 2.89%, P < 0.001), whereas the proportion of classical monocytes (CD14++CD16– monocytes) was significantly lower in syphilis patients than in healthy controls (68.97 ± 14.45% vs. 82.52 ± 4.56%, P < 0.001) (Figure 1B).