For AF, CD25 on IgD+ CD38dim (OR = 0.974, 95% CI: 0.962–0.986, P < 0.001), BAFF-R on IgD+ CD38- naive B cells (OR = 0.982, 95% CI: 0.972–0.993, P = 0.007), and CD64 on monocytes (OR = 0.982, 95% CI: 0.969–0.994, P = 0.01) were inversely correlated, indicating protective roles. This evidence concerns the gene CD38 and atrial fibrillation.