CEACAM5 and neoplasm: When serum ferritin, CA19–9 or CEA was used alone, they had smaller areas under the curve (AUCs) for evaluating malignant IPMNs than MPD diameter (AUC = 0.78, 95% CI: 0.69–0.86) or the combination of ferritin with tumor type (AUC = 0.79, 95% CI: 0.71–0.87) (Fig. 2A).