ROC curve analysis showed that the AUCs of CNPY2 isoform 2 for distinguishing stage I-IV CRC patients from healthy controls were 0.707, 0.657, 0.692 and 0.625, respectively, indicating that the AUC of stage I CRC patients is greater than those of stage II-IV CRC patients. This evidence concerns the gene CNPY2 and colorectal carcinoma.