This intronless gene encodes a protein that belongs to the forkhead family of transcription factors. Members of this family contain a conserved 100-amino acid DNA-binding 'forkhead' domain. The encoded protein functions as a thyroid transcription factor that plays a role in thyroid morphogenesis. Mutations in this gene are associated with the Bamforth-Lazarus syndrome, and with susceptibility to nonmedullary thyroid cancer-4. [provided by RefSeq, Nov 2016].