The overall purpose of this study is to analyse the expression of Tg, thyroid-stimulating hormone receptor (TSH-R), CK 19, hTERT, and onfFN transcripts in leukocytes, as well as in papillary thyroid carcinomas (PTCs) and follicular thyroid carcinomas (FTCs), respectively. The gene discussed is TSHR; the disease is differentiated thyroid carcinoma.