glands CYTOKERATINE-7 NORMAL HUMAN SKIN 3D SKIN BILAYERED EQUIVALENT 3D SKIN THREELAYERED EQUIVALENT MUC-1 NORMAL HUMAN SKIN 3D SKIN BILAYERED EQUIVALENT 3D SKIN THREELAYERED EQUIVALENT S-100 NORMAL HUMAN SKIN 3D SKIN BILAYERED EQUIVALENT 3D SKIN THREELAYERED EQUIVALENT