TTF1 + Cytokeratin 5/6 cocktail

Thyroid transcription factor 1 (TTF-1) is a homeodomain-containing transcription factor that regulates the expression of thyroid and lung-specific genes. TTF-1 is detected in small cell carcinomas, neuroendocrine carcinomas, and thyroid carcinomas. As such, TTF-1 can help identify primary pulmonary carcinomas and differentiate it from metastatic carcinomas. Keratins are intermediate filaments found in the cytoskeleton of epithelial cells. Cytokeratin (CK) 5 and 6 are both type II keratins and are associated with the differentiation of simple and stratified epithelial tissue. CK 5/6 has been documented as a useful positive marker for diagnosing malignant mesothelioma. Together, TTF-1 and CK5/6 antibodies form valuable markers to help differentiate between mesotheliomas and pulmonary adenocarcinomas.