This mAb recognizes a protein of 40kDa, identified as Thyroid transcription factor 1. TTF1 is a member of the NKx2 family of homeodomain transcription factors. It is expressed in epithelial cells of the thyroid gland and the lung. Nuclei from liver, stomach, pancreas, small intestine, colon, kidney, breast, skin, testes, pituitary, prostate, and adrenal glands are unreactive. antibody to TTF1 is useful in differentiating primary adenocarcinoma of the lung from metastatic carcinomas originating in the breast, mediastinal germ cell tumors, and malignant mesothelioma. The antibody can also be used to differentiate small cell lung carcinoma from lymphoid infiltrates. Loss of expression in non-small cell lung carcinoma has been associated with aggressive behavior of such neoplasms. TTF1 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).