Some terms link to a glossary of definitions. If you access the glossary through a link, use your Back key to return to this page. The thyroid gland has two lobes, one on either side of the neck. The thyroid gland produces hormones that regulate the body's metabolism and other functions. Each type is caused by an abnormality of a specific cell type.
Follicular cells produce thyroid hormone.
Malignant tumors of this cell type include papillary, follicular, and anaplastic thyroid cancer. Measurements of these proteins are used to diagnose and follow the progression of C-cell tumors. The tumor does not produce thyroid hormone. These changes cause the RET protooncogene to direct abnormal cell growth and tumor formation. For more information on these disorders, refer to Familial Medullary Thyroid Carcinoma - A Guide for Affected Families .