A homeobox protein and transcription factor that localizes to the cell nucleus where it activates expression of thyroid specific genes such as THYROGLOBULIN and the THYROTROPIN RECEPTOR. It is critical for maintaining thyroid tissue in a differentiated state and also plays a role in lung development. Mutations in the NKX2-1 gene are associated with CHOREA, BENIGN HEREDITARY.

Synonyms: TTF-1 Thyroid Nuclear Factor, Thyroid Nuclear Factor 1, Homeobox Protein Nkx 2.1, NK2 Homeobox 1 Protein, TITF-1 Protein, TITF 1 Protein, Nkx-2.1, Homeobox Protein, Thyroid-Specific Enhancer-Binding Protein, 0, Enhancer-Binding Protein, Thyroid-Specific, Homeobox Protein Nkx-2.1, Thyroid Specific Enhancer Binding Protein, TTF 1 Thyroid Nuclear Factor, Thyroid Transcription Factor 1, TITF1 Protein