Structural component of intermediate filaments in epithelial keratinocytes. Forms heteropolymers with the type I keratins, likely including KRT16 and KRT17, assembling keratin intermediate filament networks that contributes to the structural framework and mechanical resilience of stratified epithelia, particularly in palmoplantar epidermis. . This is the function of Ensembl gene identifier ENSG00000170465 (KRT6C, keratin 6C).