Structural component of intermediate filaments in keratinizing epithelia (PubMed:11445569). As a type II hair keratin, forms obligate heterodimers with type I keratins to assemble keratin intermediate filaments (By similarity). Expressed predominantly in the posterior compartment of the filiform papillae of the tongue, where it contributes to the structural integrity and mechanical resilience of specialized keratinized epithelial cells (Probable). {ECO:0000250|UniProtKB:P13647, ECO:0000269|PubMed:11445569, ECO:0000305|PubMed:11445569}. This is the function of Ensembl gene identifier ENSG00000161849 (KRT84, keratin 84).