Cytokeratin 17 (CK17) is 48 kD intermediate filament found in simple epithelia and is a marker for cervical reserve (stem) cells. CK17 can be useful in the identification of uterine cervical squamous lesions including atypical immature metaplasia, cervical intraepithelial neoplasia, and cervical squamous carcinoma. CK17 also assists in the differentiation of oral squamous cell carcinoma. CK17 staining occurs in human epithelial appendages such as hair follicles. Studies indicate CK17 maybe an excellent marker for the identification of squamous cell carcinomas in various tissues including the cervix, lung and oral cavity. CK17 may also be helpful in distinguishing myoepithelial cells from luminal epithelium of various glands such as mammary, sweat and salivary. Positive expression of CK17 in breast cancer has been associated with a worse prognosis, high tumor grade and positive axillary lymph nodes. Expressed in the outer root sheath and medulla region of hair follicle specifically from eyebrow and beard, digital pulp, nail matrix and nail bed epithelium, mucosal stratified squamous epithelia and in basal cells of oral epithelium, palmoplantar epidermis and sweat and mammary glands. Also expressed in myoepithelium of prostate, basal layer of urinary bladder, cambial cells of sebaceous gland and in exocervix (at protein level).
Esophageal Carcinoma Tissue
Synthetic peptide corresponding to residues within aa400-500 of Human Cytokeratin 17 was used as an immunogen.
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