CRP and atrial fibrillation: Figure 2 shows the Kaplan–Meier estimates of the sampling-to-delivery interval for a plasma IL-6 level of ≥4.8 or < 4.8 pg/mL (Fig. 2a), serum CRP level of ≥3.5 or < 3.5 mg/L (Fig. 2b), and AF IL-6 level of ≥1.5 or < 1.5 ng/mL (Fig. 2c).