Anti-KRTAP4-4 antibodies are used in the immunodetection of the protein keratin associated protein 4-4. In humans, the canonical protein has a reported length of 166 amino acid residues and a mass of 18 kDa. It is reported to be expressed in the hair follicles. It is a member of the KRTAP type 4 protein family. Synonyms for this target antigen include keratin-associated protein 4-13, keratin-associated protein 4.13, ultrahigh sulfur keratin-associated protein 4.13, ultrahigh sulfur keratin-associated protein 4.4, and keratin associated protein 4.4.