IL37 and periodontitis: However, within-group analyses revealed several meaningful correlations: IL-23 was positively associated with clinical attachment loss (CAL) in healthy individuals (r = 0.548, p = 0.019); IL-35 showed a negative correlation with the plaque index in the T2DM-only group (r = −0.578, p = 0.012); and IL-23 was inversely correlated with ESR and CRP in the periodontitis subgroups (r ≈ −0.49, p < 0.05) [66].