This gene is a member of the type II keratin family clustered on the long arm of chromosome 12. Type I and type II keratins heteropolymerize to form intermediate-sized filaments in the cytoplasm of epithelial cells. This gene is expressed in the companion layer, upper germinative matrix region of the hair follicle, and medulla of the hair shaft. The encoded protein plays an essential role in hair and nail formation. Variations in this gene have been associated with the hair disorders pseudofolliculitis barbae (PFB) and loose anagen hair syndrome (LAHS). [provided by RefSeq, Oct 2008].