Fig. 4. Histology of line 2 K5-Klf4 DT epidermis during development. Control and line 2 K5-Klf4 DT epidermis at the ages indicated were fixed in paraformaldehyde, embedded in paraffin, sectioned and stained with Hematoxylin and Eosin. The K5-Klf4 DT epidermis has accelerated differentiation with normal histology. Similar results were obtained for all three lines except that lines 6 and 10 had more advanced granular and SC layers at E15.5 than line 2. The dotted line indicates the basement membrane.