Cytokeratin Pan

Cytokeratin Pan (AE1/AE3) is a mixed biomarker consisting of cytokeratin AE1 and AE3. Among them, AE1 can label most acidic keratin, while AE3 can label all known alkaline keratin. AE1/AE3 is widely expressed in almost all simple epithelium, stratified epithelium, and transitional epithelium, so it has become a diagnostic indicator for squamous cell carcinoma, adenocarcinoma, transitional cell carcinoma, and other epithelial derived tumors in clinical practice, which has important significance for tumor origin detection. Meanwhile, AE1/AE3 is positive in some mesenchymal tumors such as mesothelioma, synovial sarcoma, and leiomyosarcoma, indicating that the tumor cells have epithelioid differentiation characteristics. Moreover, AE1/AE3 immunohistochemistry is considered as an effective detection method for tumor micrometastases, and its expression in lymph nodes suggests the tumors have higher risk and recurrence rate. However, some scholars pointed out that high expression of AE1/AE3 is a good prognostic factor for patients with small cell lung cancer, but the specific mechanism is still unclear.