The Ct-based ROC curve analysis (Figure 3A; Table 4) showed that, for CRC vs. normal, the AUC value of SDC2/TFPI2-combined detection was 0.98 (95% CI: 0.96–0.99) with the specificity of 96.40% and sensitivity of 96.60%, while the AUC value of SDC2 detection was 0.88 (95% CI: 0.85–0.92) with the specificity of 100% and sensitivity of 78.60%. This evidence concerns the gene TFPI2 and colorectal carcinoma.