GDF15 and colorectal carcinoma: The serum MIC-1 (AUC: 0.843, 95%CI: 0.814-0.869) showed a better performance compared with CEA (AUC: 0.658, 95%CI: 0.621-0.693; P<0.0001) for distinguishing early-stage CRC from normal controls (Figure 2B) by ROC curve analysis.