CEACAM5 and thyroid nodule: In this study, the use of TAP + CEA for the detection of patients with thyroid nodules of type IV and above is discussed, and it was found that the sensitivity, specificity, and accuracy of TAP + CEA detection are 96.84%, 96.79%, and 97.89%, which are higher than the sensitivity, specificity, and accuracy of serum TAP detection and serum CEA detection.