One review article summarized and discussed the power of combining CTC counts with other clinical parameters (e.g., CTC, CTC subtypes, CEA, carbohydrate antigen-199 (CA-199)) in predicting CRC recurrence to improve the accuracy of cancer detection, prognostic evaluation, and therapeutic response monitoring in numerous malignancies, including CRC [128]. The gene discussed is CEACAM5; the disease is cancer.