SLC5A5 and thyroid gland carcinoma: Utility of thyroid-specific mRNA transcripts such as thyroid peroxidase (TPO), sodium-iodide symporter (NIS), thyroglobulin (TG), and thyroid stimulating hormone receptor (TSHR) in predicting thyroid cancer recurrences and metastases had been assessed previously using whole blood (Barzon et al., 2004).