The function of KRT81 (keratin 81, ENSG00000205426) is as follows. Structural component of intermediate filaments in the hair cortex (PubMed:10504448, PubMed:9402962). Forms obligate heterodimers with type I hair keratins, which assemble into keratin intermediate filaments that contribute to the structural integrity and mechanical strength of the hair shaft (PubMed:10504448, PubMed:9402962). .