特異性：Keratin 191 Keratins are a family of intermediate filament proteins that assemble into filaments through forming heterodimers of one type I keratin (keratins 9 to 23) and one type II keratin (keratins 1-8). The two keratin types share only 30% sequence homology.2-6 Keratins demonstrate tissue- and differentiation-specific expression profiles. Cytokeratin 19 is the smallest human keratin, is found in many simple and some non-keratinizing stratified squamous epithelia, and is often co-expressed with keratin 7.7,8 Cytokeratin 19 has been implicated as a marker for stem cells in some tissues, such as hair follicles in the skin. Monoclonal antibodies to cytokeratin proteins can be useful markers for tumor identification and classification. The degree of cytokeratin 19 positivity in breast cancer distinguishes malignant from benign tumors. Cytokeratin 19 is also associated with malignant transformation in esophageal and pancreatic cancers.9,10
