Thyroid transcription factor 1
Thyroid transcription factor 1 (TTF1) refers to a homeodomain-containing nuclear transcription factor which belongs to the Nkx2 gene family encoded by a gene located on chromosome 14q13.
It is expressed in the forebrain, thyroid and lung tissues. The presence of TTF-1 protein on a tissue sample is useful in the diagnosis of lung cancer and can be expressed in up to 90% of pulmonary small cell carcinoma but usually not in squamous cell carcinoma.
It is rarely expressed in some primary extrapulmonary tumors .
Some publications suggest its "overexpression" may result a more favorable overall prognosis.