FOXE1 and hypothyroidism: A genetic overlap was observed between susceptibility loci identified in GWAS for AITD or hypothyroidism and GWAS for thyroid function, including FOXE1, CAPZB, and PDE8B. FOXE1, also known as TTF-2 (thyroid transcription factor 2), is associated with hypothyroidism, and with TSH and fT4 levels, as well as with thyroid cancer (133, 143, 158, 162).