TPO and thyroid cancer: FOXE1 regulates the transcription of thyroglobulin (TG), thyroperoxidase (TPO), NKX2.1, PAX8, Sodium/Iodine Symporter (NIS), and DUOX2, genes required for hormone synthesis (4, 5), and also regulates PDGFA (6) and ZEB1 in thyroid cancer (7).