Analysis of circulating IL-8 showed that plasma levels of this chemokine differed significantly between the T1DM+CP/T2DM+CP patients (median [interquartile range, IQR]: 15.09 pg/mL [9.73–20.32]/14.25 pg/mL [11.72–23.36], respectively) and non-periodontitis HC (10.53 pg/mL [8.48–12.58], P < 0.01 in both comparisons). The gene discussed is CXCL8; the disease is type 2 diabetes mellitus.