(2) AF MMP-8 concentrations continuously elevated according to the progression of inflammation in CP [stage-0 vs. stage-1 vs. stage-2 vs. stage-3; median (ng/ml), range (ng/ml); 6.0 (0.3–4202.7) vs. 153.9 (0.3–6142.6) vs. 464.9 (5.8–3929.0) vs. 1,780.4 (35.1–5019.5); Kruskal–Wallis test, P < 0.001 and Spearman's rank-correlation test, P < 0.000001, r = 0.553]. The gene discussed is MMP8; the disease is atrial fibrillation.