research K25 (K25irs1), K26 (K25irs2), K27 (K25irs3), and K28 (K25irs4) Represent the Type I Inner Root Sheath Keratins of the Human Hair Follicle
This study describes the expression patterns of type I inner root sheath keratin proteins K25–K28 in human hair follicles, highlighting their distinct distribution within different layers.