This gene encodes a member of the keratin-associated protein (KAP) family. The KAP proteins form a matrix of keratin intermediate filaments which contribute to the structure of hair fibers. KAP family members appear to have unique, family-specific amino- and carboxyl-terminal regions and are subdivided into three multi-gene families according to amino acid composition: the high sulfur, the ultrahigh sulfur, and the high tyrosine/glycine KAPs. This gene encodes a member of the high sulfur KAP family. It is localized to a cluster of intronless KAPs at 21q22.3 which are located within the introns of the C21orf29 gene. [provided by RefSeq, Jul 2008]