ROC curves for patients with post-HCT diarrhea. ROC curves comparing REG3α concentrations for patients with diarrhea caused by GVHD (n = 162) and not caused by GVHD (N = 42). REGα alone (thick blue): AUC = 0.80; IL2Rα (thick brown): AUC = 0.69; Elafin (thick red): AUC = 0.68; IL-8 (thin blue): AUC = 0.61; HGF (thin brown): AUC = 0.61; TNFR1 (thin red): AUC = 0.60; composite of all 6 biomarkers (solid black): AUC = 0.81.