CEACAM5 and colorectal carcinoma: Several approaches involving colonoscopy, sigmoidoscopy, fecal occult blood test (FOBT) [2, 8], serum biomarkers such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) [9], together with Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) [10] are commonly used to screen or diagnose CRC.