Identification of carcinoembryonic antigen in the C-Cell of the normal thyroid

Abstract
Carcinoembryonic antigen (CEA) activity was confirmed in the C‐cell of the normal thyroid by immunohistochemical techniques. This suggests that CEA production in medullary carcinoma of the thyroid is not initiated by carcinogenesis, but reflects a function of the normal C‐cell. It is not yet clear whether CEA production in the C‐cell may be influenced by carcinogenesis. The C‐cell is the first APUD cell that was confirmed to have CEA activity.