Anti-Cytokeratin 17, clone SPM560

0.2 mg/ml in 1X PBS with 0.1 mg/ml BSA (US sourced) and 0.05% sodium azide. Cytokeratin 17 (CK17) is a member of the Cytokeratin subfamily of intermediate filament proteins (IF's). It is unique in that it is normally expressed in the basal cells of complex epithelia but not in stratified or simple epithelia. CK17 is expressed in the nail bed, hair follicle, sebaceous glands and other epidermal appendages. Antibody to CK17 is an excellent tool to distinguish myoepithelial cells from luminal epithelium of various glands such as mammary, sweat and salivary. CK17 is expressed in epithelial cells of various origins, such as bronchial epithelial cells and skin appendages. It may be considered an epithelial stem cell marker because CK17 Ab marks basal cell differentiation. CK17 can be useful when included in a panel of antibodies against TTF-1, napsin A, CK5&6, p63, and SOX-2 for diagnostic differentiation between lung adenocarcinoma (LADC) and lung squamous cell carcinoma (SCLC), especially for poorly-differentiated lung carcinoma. CK17 is expressed in SCLC much higher than in LADC. In breast carcinomas, approximately 20% of patients show no expression of ER, PR and Her2, which are defined as triple negative tumor. Eighty-five percent of the triple negative breast carcinomas immunoreact with basal cytokeratins including anti-CK17. Also important is that cases of triple negative breast carcinoma with expression of CK17 show an aggressive clinical course. The histologic differentiation of ampullary cancer, intestinal vs. pancreatobiliary, is very important for treatment. Usually anti-CK17 and anti-MUC1 immunoreactivity represents pancreatobiliary subtype whereas anti-MUC2 and anti-CDX-2 positivity defines intestinal subtype. Protein function: Type I keratin involved in the formation and maintenance of various skin appendages, specifically in determining shape and orientation of hair. Required for the correct growth of hair follicles, in particular for the persistence of the anagen (growth) state. Modulates the function of TNF-alpha in the specific context of hair cycling. Regulates protein synthesis and epithelial cell growth through binding to the adapter protein SFN and by stimulating Akt/mTOR pathway. Involved in tissue repair. May be a marker of basal cell differentiation in complex epithelia and therefore indicative of a certain type of epithelial "stem cells". Acts as a promoter of epithelial proliferation by acting a regulator of immune response in skin: promotes Th1/Th17-dominated immune environment contributing to the development of basaloid skin tumors. May act as an autoantigen in the immunopathogenesis of psoriasis, with certain peptide regions being a major target for autoreactive T-cells and hence causing their proliferation. [The UniProt Consortium]