ROC curve analysis showed that these 20 genes have high diagnostic value for CRC: CLCA1 AUC= 0.959, TMIGD1 AUC= 0.998, SLC30A10 AUC= 0.993, MT1F AUC= 0.933, MT1M AUC= 0.975, MT1G AUC= 0.944, MT1H AUC= 0.947, MT1E AUC= 0.943, GUCA2B AUC= 0.991, GUCA2A AUC= 0.99, SLC26A3 AUC= 0.989, CLCA4 AUC= 0.984, MS4A12 AUC= 0.978, SI AUC= 0.94, SLC9A2 AUC= 0.959, GCG AUC= 0.992, PYY AUC= 0.993, SST AUC= 0.992, SLC4A4 AUC= 0.997, and SLC16A9 AUC= 0.903 (Figure 6B). The gene discussed is CLCA1; the disease is colorectal carcinoma.