Has a role in hair formation. Specific component of keratin intermediate filaments in the inner root sheath (IRS) of the hair follicle (Probable).
Highly expressed in hair follicles from scalp and eyebrow. Also expressed in palmoplantar epidermis. Not expressed in face skin despite the presence of fine hairs histologically. In hair, it is specifically present in the inner root sheath (IRS) of the hair follicle. Present in the IRS cuticle, but not in Henle or Huxley layers of the IRS. In the IRS cuticle, its presence is delayed up to the height of the apex of the dermal papilla (at protein level).