SLC6A3 and periodontitis: As shown in Figure 6C, the AUC for CDSN, TH, DDC, and SLC6A3 in periodontitis patients and normal controls were 0.889 (95% confidence interval [CI], 0.581–1.000, p < 0.05), 0.444 (95% CI, 0.000–1.000; p < 0.05), 0.778 (95% CI, 0.291–1.000; p < 0.05), and 0.778 (95% CI, 0.291–1.000; p < 0.05), respectively.