As stated in the 1996 American Thyroid Association (ATA) guidelines, surgery and radioactive iodine therapy can treat most patients with differentiated thyroid cancer, but there are a few patients with rapid growth, extensive metastases, and even life-threatening tumors, for whom experimental therapy is indicated. The current understanding of the molecular and cytological pathogenesis of thyroid cancer has led to the clinical evaluation of several targeted therapies, including oncogene inhibition, growth or apoptosis regulation, inhibition of angiogenesis, immunomodulation, and gene therapy.