Fig. 2

a Eotaxin and Rantes; b IL27 and Leptin; and c Il1RA and Trail. *The three pairs of cytokines that could best distinguish between people with incident syphilis versus people without syphilis. a The measurements for each cytokine were divided into tertiles, indicated by the light gray lines. Of the diagonally opposing pairs corners, RANTES low:EOTAXIN low (pink) and RANTES high:EOTAXIN high (green) contain more observations than did RANTES low:EOTAXIN high and RANTES high:EOTAXIN low. This lower left-hand corner (pink) contains 2 “no infection” samples and 9 “yes infection” samples. The right-hand corner (green) contains 12 “no infection” values and 3 “yes infection.” This difference is statistically significant, suggesting that samples with RANTES low and EOTAXIN low are more likely to suggest infection, while RANTES high and EOTAXIN high are more likely to suggest no infection. The title provides the Chi square p-value and number of observations in the highlighted corners corners. “No infection” samples are shown as circles while “yes infection” samples are shown as squares. Shading indicates samples from patients who are HIV+. The table on the right side of the graph shows counts of “no” and “yes” samples by corner. Black lines along the axes indicated observed values for that cytokine and represent the distribution of observed values. b Analysis as per A, for LEPTIN and IL27. c Analysis as per A, for TRAIL and ILRA