Specific for human keratin K71 (57.3 kD polypeptide, calculated from sequence data).The antiserum stains specifically the Henle, Huxley and cuticle layer of the inner root sheath (irs) of the hair follicle. Although there is a considerable sequence homology of keratin K71 to keratins K5 andK 6, no cross-reactivity was observed with Western blotting and immunofluorescence microscopy.