the cytokeratin family of intermediate filament ( if ) proteins can be grouped into the epithelial polypeptides ( `` '' soft alpha-keratins '' '' ) , of which at least 19 exist in the various human epithelia , and the hair-type cytokeratins ( `` '' hard alpha-keratins '' '' ) , which are typical of trichocytes , i.e. , the living hair-forming cells .
C0014609
n epithel
C0018496