TTF-1 (8G7G3/1)

Anti-TTF-1 (Thyroid Transcription Factor 1) is useful in differentiating primary adenocarcinoma of the lung from metastatic carcinomas originating in the organs rather than thyroid1-2, germ cell tumors3, and malignant mesothelioma.4-5 It can also be used to differentiate small cell lung carcinoma from lymphoid infiltrates.6 TTF-1 labeling is also seen in thyroid and thyroid-derived tumors.7 TTF-1 immunostaining is useful in the differentiation between pulmonary and nonpulmonary origin of adenocarcinomas in malignant effusions.8 TTF-1 staining is very reliable in discerning whether a brain metastasis has arisen from a pulmonary or nonpulmonary site, particularly when dealing with adenocarcinomas and large-cell carcinomas.9