CEACAM5 and neoplasm: Carcinoembryonic antigen (CEA), which has been the first blood marker proposed in connection with CRC [39], overall sensitivity varied between 43% and 69%, and the most other common tumor markers for CRC, overall sensitivity ranged 18% to 65% for Carbohydrate antigen 19-9 (CA19-9) and 30% to 55% carbohydrate antigen 242 (CA242) [40].