The function of Ensembl gene identifier ENSG00000171403 (KRT9, keratin 9) is as follows. Structural component of intermediate filaments in suprabasal keratinocytes of palmoplantar epidermis. Forms heteropolymers with a type II keratin, assembling into keratin intermediate filament networks that maintain the mechanical integrity of the palmoplantar epidermis. {ECO:0000269|PubMed:10218578, ECO:0000269|PubMed:7507869, ECO:0000269|PubMed:7512862}.