Keratin 9 is a protein that in humans is encoded by the KRT9 gene.
Keratin 9 is a type I cytokeratin. It is found only in the terminally differentiated epidermis of palms and soles. Mutations in the gene encoding this protein cause KRT9-palmoplantar epidermal differentiation disorder (KRT9-pEDD), formerly known as epidermolytic palmoplantar keratoderma or Vorner disease.
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