Background：The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells. KRT19, one of type I keratins, is specifically expressed in the periderm, the transiently superficial layer that envelopes the developing epidermis. Due to its high sensitivity, KRT19 is the most used marker for detection of tumor cells disseminated in lymph nodes, peripheral blood, and bone marrow of breast cancer patients.Keratin 19 is a type I cytokeratin. It is a biochemical marker of skin stem cells in vivo and in vitro.
