Firstly, as thyroid cancer becomes poorly differentiated, cells no longer express Tg, making it a less reliable marker of recurrence [7]; up to 15% of patients with stimulated Tg < 1ug/L were found to have a distant metastasis, with lower Tg seen in tumors with an aggressive histology and BRAFV600E mutations [8,9]. Here, TG is linked to thyroid gland carcinoma.