Another study using ROC curves to comparing the specificity and sensitivity of CEA and CA19-9 in the early diagnosis of CRC, the AUC of CEA is 0.797 (P < 0.001) and the AUC of CA19-9 is 0.664 (P = 0.001) 7. The gene discussed is CEACAM5; the disease is colorectal carcinoma.