Thyroid transcription factor-1 is a member of the NKx2 family of homeodomain transcription factors. It is expressed in epithelial cells of the thyroid gland and the lung. Anti-TTF-1 is useful in differentiating primary adenocarcinoma of the lung from metastatic carcinomas originating in the breast, mediastinal germ cell tumors, and malignant mesothelioma. TTF-1 reactivity is also seen in thyroid malignancies.

Store the TTF-1 antibody at 2-8°C (with azide) or aliquot and store at -20°C or colder (without azide).