Cytokeratin 17 (KRT17, CK17) is an Type I basal cytokeratin that is found in the nail bed, hair follicle, sebaceous glands, squamous epithelia of the skin, esophagus, tonsil and oral mucosa, the urinary bladder, salivary gland, breast, prostate, and respiratory tract. Mutations in this gene result in Jackson-Lawler pachyonychia congenital and steatocystoma multiplex. KRT17 has been implicated in the growth of oral squamous carcinomas through an anti-apoptotic mechanism. It is positive in a variety of different cancers. References: PLos One 2016 11(8):e0161163; J Cancer Res Clin Oncol 2017 143(8): 1381; J Dermatol 2006 33:161; Br J Dermat 1998 139:475